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2022 Volume 33 Issue 5
2022, 33(5): 2213-2230
doi: 10.1016/j.cclet.2021.11.048
Abstract:
Chemodynamic therapy (CDT), defined as an in situ oxidative stress response catalyzed by the Fenton or Fenton-like reactions to generate cytotoxic hydroxyl radicals (•OH) at tumor sites, exhibits conspicuous inhibition of tumor growth. It has attracted extensive attention for its outstanding edge in effectiveness, lower systemic toxicity and side effects, sustainability, low cost and convenience. However, the inconformity of harsh Fenton reaction conditions and tumor microenvironment hamper its further development, based on which, numerous researchers have made efforts in further improving the efficiency of CDT. In this review, we expounded antitumor capacity of CDT in mechanism, together with its limitation, and then summarized and came up with several strategies to enhance CDT involved tumor therapy strategies by 1) improving catalytic efficiency; 2) increasing hydrogen peroxide levels at tumor sites; 3) reducing glutathione levels at tumor sites; 4) applying external energy intervention; 5) amplifying the distribution of hydroxyl radicals at tumor sites; and 6) combination therapy. Eventually, the perspectives and challenges of CDT are further discussed to encourage more in-depth studies and rational reflections.
Chemodynamic therapy (CDT), defined as an in situ oxidative stress response catalyzed by the Fenton or Fenton-like reactions to generate cytotoxic hydroxyl radicals (•OH) at tumor sites, exhibits conspicuous inhibition of tumor growth. It has attracted extensive attention for its outstanding edge in effectiveness, lower systemic toxicity and side effects, sustainability, low cost and convenience. However, the inconformity of harsh Fenton reaction conditions and tumor microenvironment hamper its further development, based on which, numerous researchers have made efforts in further improving the efficiency of CDT. In this review, we expounded antitumor capacity of CDT in mechanism, together with its limitation, and then summarized and came up with several strategies to enhance CDT involved tumor therapy strategies by 1) improving catalytic efficiency; 2) increasing hydrogen peroxide levels at tumor sites; 3) reducing glutathione levels at tumor sites; 4) applying external energy intervention; 5) amplifying the distribution of hydroxyl radicals at tumor sites; and 6) combination therapy. Eventually, the perspectives and challenges of CDT are further discussed to encourage more in-depth studies and rational reflections.
2022, 33(5): 2231-2242
doi: 10.1016/j.cclet.2021.08.105
Abstract:
Biomedicine is one of the fastest growing areas of additive manufacturing. Especially, in the field of in vitro diagnostics (IVD), contributions of 3D printing include ⅰ) rapid prototyping and iterative IVD proof-of-concept designing ranging from materials, devices to system integration; ⅱ) conceptual design simplification and improved practicality of IVD products; ⅲ) shifting the IVD applications from centralized labs to point-of-care testing (POCT). In this review, the latest developments of 3D printing and its advantages in IVD applications are summarized. A series of 3D-printed objects for IVD applications, including single-function modules, multi-function devices which integrate several single-function modules for specific analytical applications such as sample pre-treatment and chemo-/bio-sensing, and all-in-one systems which integrate multi-function devices and the instrument operating them, are analyzed from the perspective of functional integration. The current and potential commercial applications of 3D-printed objects in the IVD field are highlighted. The features of 3D printing, especially rapid prototyping and low start-up, enable the easy fabrication of bespoke modules, devices and systems for a range of analytical applications, and broadens the commercial IVD prospects.
Biomedicine is one of the fastest growing areas of additive manufacturing. Especially, in the field of in vitro diagnostics (IVD), contributions of 3D printing include ⅰ) rapid prototyping and iterative IVD proof-of-concept designing ranging from materials, devices to system integration; ⅱ) conceptual design simplification and improved practicality of IVD products; ⅲ) shifting the IVD applications from centralized labs to point-of-care testing (POCT). In this review, the latest developments of 3D printing and its advantages in IVD applications are summarized. A series of 3D-printed objects for IVD applications, including single-function modules, multi-function devices which integrate several single-function modules for specific analytical applications such as sample pre-treatment and chemo-/bio-sensing, and all-in-one systems which integrate multi-function devices and the instrument operating them, are analyzed from the perspective of functional integration. The current and potential commercial applications of 3D-printed objects in the IVD field are highlighted. The features of 3D printing, especially rapid prototyping and low start-up, enable the easy fabrication of bespoke modules, devices and systems for a range of analytical applications, and broadens the commercial IVD prospects.
2022, 33(5): 2243-2252
doi: 10.1016/j.cclet.2021.08.096
Abstract:
Droplet-based microfluidics enables the generation of uniform microdroplets at picoliter or nanoliter scale with high frequency (~kHz) under precise control. The droplets can function as bioreactors for versatile chemical/biological study and analysis. Taking advantage of the discrete compartment with a confined volume, (1) isolation and manipulation of a single cell, (2) improvement of in-droplet effective concentrations, (3) elimination of heterogeneous population effects, (4) diminution of contamination risks can be achieved, making it a powerful tool for rapid, sensitive, and high-throughput detection and analysis of bacteria, even for rare or unculturable strains in conventional methods. This mini-review will focus on the generation and manipulation of micro-droplets and bacteria detection and analysis carried out by droplet-based microfluidics. Finally, applications with high potential of droplet-based bacteria analysis are briefly introduced. Due to the advantages of rapid, sensitive, high throughput, and compatibility with rare and unculturable bacteria in conventional methods, droplet-based microfluidics has tremendous potential of providing novel solutions for biological medicine, microbiological engineering, environmental ecology, etc.
Droplet-based microfluidics enables the generation of uniform microdroplets at picoliter or nanoliter scale with high frequency (~kHz) under precise control. The droplets can function as bioreactors for versatile chemical/biological study and analysis. Taking advantage of the discrete compartment with a confined volume, (1) isolation and manipulation of a single cell, (2) improvement of in-droplet effective concentrations, (3) elimination of heterogeneous population effects, (4) diminution of contamination risks can be achieved, making it a powerful tool for rapid, sensitive, and high-throughput detection and analysis of bacteria, even for rare or unculturable strains in conventional methods. This mini-review will focus on the generation and manipulation of micro-droplets and bacteria detection and analysis carried out by droplet-based microfluidics. Finally, applications with high potential of droplet-based bacteria analysis are briefly introduced. Due to the advantages of rapid, sensitive, high throughput, and compatibility with rare and unculturable bacteria in conventional methods, droplet-based microfluidics has tremendous potential of providing novel solutions for biological medicine, microbiological engineering, environmental ecology, etc.
2022, 33(5): 2253-2258
doi: 10.1016/j.cclet.2021.08.109
Abstract:
DNA methylation represents a major type of DNA modifications that play key roles in diverse biological processes. With the recent development of highly selective and sensitive bioanalytical techniques, N6-methyladenine (6mA) has been characterized as an important internal DNA modification dynamically occurring in multiple eukaryotes including humans. Increasing evidence has indicated that 6mA may act as a novel epigenetic modification involved in regulation of development, stress response and diseases such as cancer and neurodegenerative disorders. We review herein the recent advances in the detection and functional studies of 6mA modification, with special emphasis on its biological consequences and human health relevance as well as its dynamic regulation by various types of methyltransferases, demethylases and 6mA-binding proteins. It can be envisaged that further chemical and biological studies of 6mA modification will lead to a better understanding about its potentially important roles in normal and pathological biological processes.
DNA methylation represents a major type of DNA modifications that play key roles in diverse biological processes. With the recent development of highly selective and sensitive bioanalytical techniques, N6-methyladenine (6mA) has been characterized as an important internal DNA modification dynamically occurring in multiple eukaryotes including humans. Increasing evidence has indicated that 6mA may act as a novel epigenetic modification involved in regulation of development, stress response and diseases such as cancer and neurodegenerative disorders. We review herein the recent advances in the detection and functional studies of 6mA modification, with special emphasis on its biological consequences and human health relevance as well as its dynamic regulation by various types of methyltransferases, demethylases and 6mA-binding proteins. It can be envisaged that further chemical and biological studies of 6mA modification will lead to a better understanding about its potentially important roles in normal and pathological biological processes.
2022, 33(5): 2259-2269
doi: 10.1016/j.cclet.2021.08.074
Abstract:
Electrochemical carbon dioxide reduction (CO2RR) plays an important role in solving the problem of high concentration of CO2 in the atmosphere and realizing carbon cycle. Core-shell structure has many unique features including tandem catalysis, lattice strain effect, defect engineering, which exhibit great potential in electrocatalysis. In this review, we focus on the advanced core-shell metal-based catalysts (CMCs) for electrochemical CO2RR. The recent progress of CMCs in electrocatalytic CO2RR is described as the following aspects: (1) The mechanism of electrochemical CO2RR and evaluation parameters of electrocatalyst performance, (2) preparation methods of core-shell metal catalysts and core-shell structural advantages and (3) advanced CMCs towards electrochemical CO2RR. Finally, we make a brief conclusion and propose the opportunities and challenges in the field of electrochemical CO2RR.
Electrochemical carbon dioxide reduction (CO2RR) plays an important role in solving the problem of high concentration of CO2 in the atmosphere and realizing carbon cycle. Core-shell structure has many unique features including tandem catalysis, lattice strain effect, defect engineering, which exhibit great potential in electrocatalysis. In this review, we focus on the advanced core-shell metal-based catalysts (CMCs) for electrochemical CO2RR. The recent progress of CMCs in electrocatalytic CO2RR is described as the following aspects: (1) The mechanism of electrochemical CO2RR and evaluation parameters of electrocatalyst performance, (2) preparation methods of core-shell metal catalysts and core-shell structural advantages and (3) advanced CMCs towards electrochemical CO2RR. Finally, we make a brief conclusion and propose the opportunities and challenges in the field of electrochemical CO2RR.
2022, 33(5): 2270-2280
doi: 10.1016/j.cclet.2021.09.037
Abstract:
The increase of atmospheric CO2 concentration has caused many environmental issues. Electrochemical CO2 reduction reaction (CO2RR) has been considered as a promising strategy to mitigate these challenges. The electrocatalysts with a low overpotential, high Faradaic efficiency, and excellent selectivity are of great significance for the CO2RR. Carbon-based materials including metal-free carbon catalysts and metal-based carbon catalysts have shown great potential in the CO2RR, owing to the tailorable porous structures, abundant natural resources, resistance to acids and bases, high-temperature stability, and environmental friendliness. In this review, various carbon materials including graphene, carbon nanotubes, quantum dots, porous carbon, and MOF-derived catalysts, etc., for the CO2RR have been summarized. Particularly, recent progress in terms of the mechanism and pathway of CO2 conversion has been comprehensively reviewed. Finally, the opportunities and challenges of carbon-based electrocatalysts for the CO2RR are proposed.
The increase of atmospheric CO2 concentration has caused many environmental issues. Electrochemical CO2 reduction reaction (CO2RR) has been considered as a promising strategy to mitigate these challenges. The electrocatalysts with a low overpotential, high Faradaic efficiency, and excellent selectivity are of great significance for the CO2RR. Carbon-based materials including metal-free carbon catalysts and metal-based carbon catalysts have shown great potential in the CO2RR, owing to the tailorable porous structures, abundant natural resources, resistance to acids and bases, high-temperature stability, and environmental friendliness. In this review, various carbon materials including graphene, carbon nanotubes, quantum dots, porous carbon, and MOF-derived catalysts, etc., for the CO2RR have been summarized. Particularly, recent progress in terms of the mechanism and pathway of CO2 conversion has been comprehensively reviewed. Finally, the opportunities and challenges of carbon-based electrocatalysts for the CO2RR are proposed.
2022, 33(5): 2281-2290
doi: 10.1016/j.cclet.2021.08.086
Abstract:
Two-dimensional (2D) layered materials provide a promising alternative solution for overcoming the scaling limits in conventional Si-based devices. However, practical applications of 2D materials are facing crucial bottlenecks, particularly that arising from the instability under ambient condition. The studies of degradation mechanisms and protecting strategies for overcoming the ambient instability of 2D materials have attracted extensive research attentions, both experimentally and theoretically. This review attempts to provide an overview on the recent progress of the encapsulation strategies for 2D materials. The encapsulation strategies of mechanical transfer, polymer capping, atomic layer deposition, in-situ oxidation, and surface functionalization are systematically discussed for improving the ambient stability of 2D materials. In addition, the current advances in air-stable and high-performance 2D materials-based field effect transistors (FETs) and photodetectors assisted by the encapsulation strategies are outlined. Furthermore, the future directions of encapsulation techniques of 2D materials for FETs and photodetectors applications are suggested.
Two-dimensional (2D) layered materials provide a promising alternative solution for overcoming the scaling limits in conventional Si-based devices. However, practical applications of 2D materials are facing crucial bottlenecks, particularly that arising from the instability under ambient condition. The studies of degradation mechanisms and protecting strategies for overcoming the ambient instability of 2D materials have attracted extensive research attentions, both experimentally and theoretically. This review attempts to provide an overview on the recent progress of the encapsulation strategies for 2D materials. The encapsulation strategies of mechanical transfer, polymer capping, atomic layer deposition, in-situ oxidation, and surface functionalization are systematically discussed for improving the ambient stability of 2D materials. In addition, the current advances in air-stable and high-performance 2D materials-based field effect transistors (FETs) and photodetectors assisted by the encapsulation strategies are outlined. Furthermore, the future directions of encapsulation techniques of 2D materials for FETs and photodetectors applications are suggested.
2022, 33(5): 2291-2300
doi: 10.1016/j.cclet.2021.10.011
Abstract:
With the development of nanotechnology and materials science, bioinspired nanochannels appeared by mimicking the intelligent functions of biological ion channels. They have attracted a great deal of attention in recent years due to their controllable structure and tunable chemical properties. Inspired by the layered microstructure of nacre, 2D layered materials as excellent matrix material of nanochannel come into our field of vision. Bionic nanochannels based on 2D materials have the advantages of facile preparation, tunable channel size and length, easy expansion, and modification, etc. Therefore, the 2D layered nanofluid system based on bionic nanochannels from 2D layered materials has great potential in biomimetic microsensors, membrane separations, energy conversion, and so on. In this paper, we focus on the construction and application of bionic nanochannels based on 2D layer materials. First, a basic understanding of nanochannels based on 2D materials is briefly introduced, we also present the property of the 2D materials and construction strategies of bionic nanochannels. Subsequently, the application of these nanochannels in responsive channels and energy conversion is discussed. The unsolved challenges and prospects of 2D materials-based nanochannels are proposed in the end.
With the development of nanotechnology and materials science, bioinspired nanochannels appeared by mimicking the intelligent functions of biological ion channels. They have attracted a great deal of attention in recent years due to their controllable structure and tunable chemical properties. Inspired by the layered microstructure of nacre, 2D layered materials as excellent matrix material of nanochannel come into our field of vision. Bionic nanochannels based on 2D materials have the advantages of facile preparation, tunable channel size and length, easy expansion, and modification, etc. Therefore, the 2D layered nanofluid system based on bionic nanochannels from 2D layered materials has great potential in biomimetic microsensors, membrane separations, energy conversion, and so on. In this paper, we focus on the construction and application of bionic nanochannels based on 2D layer materials. First, a basic understanding of nanochannels based on 2D materials is briefly introduced, we also present the property of the 2D materials and construction strategies of bionic nanochannels. Subsequently, the application of these nanochannels in responsive channels and energy conversion is discussed. The unsolved challenges and prospects of 2D materials-based nanochannels are proposed in the end.
2022, 33(5): 2301-2315
doi: 10.1016/j.cclet.2021.11.089
Abstract:
Complex coordinated functional groups [MAxBy] (M = Central coordination element; A, B = P, O, S, Se, F, Cl, Br or I) are composed of different types of anions A, B jointly linked to the same central cation M, which are in high potential to tune the physical properties of materials, e.g., second-order susceptibility, energy gaps and birefringence. Recently, Compound containing complex coordinated functional groups have attracted great attention in the nonlinear optical (NLO) field and a large number of this type crystals exhibit promising NLO performance. However, the inherent relationship between ionic group structure and optical properties of complex coordinated NLO materials have not been systematically studied. This article systematically summarizes complex coordinated NLO materials in recent five years from the perspective of the internal relationship between crystal structure and optical properties. In addition, we propose the ideal combination and arrangement modes for structural building units, and also reveal the influence of complex coordinated functional groups [MAxBy] toward the NLO response, optical band gap and phase matching ability of complex coordinated NLO materials.
Complex coordinated functional groups [MAxBy] (M = Central coordination element; A, B = P, O, S, Se, F, Cl, Br or I) are composed of different types of anions A, B jointly linked to the same central cation M, which are in high potential to tune the physical properties of materials, e.g., second-order susceptibility, energy gaps and birefringence. Recently, Compound containing complex coordinated functional groups have attracted great attention in the nonlinear optical (NLO) field and a large number of this type crystals exhibit promising NLO performance. However, the inherent relationship between ionic group structure and optical properties of complex coordinated NLO materials have not been systematically studied. This article systematically summarizes complex coordinated NLO materials in recent five years from the perspective of the internal relationship between crystal structure and optical properties. In addition, we propose the ideal combination and arrangement modes for structural building units, and also reveal the influence of complex coordinated functional groups [MAxBy] toward the NLO response, optical band gap and phase matching ability of complex coordinated NLO materials.
2022, 33(5): 2316-2326
doi: 10.1016/j.cclet.2021.09.077
Abstract:
Among the large energy storage batteries, the sodium ion batteries (SIBs) are attracted huge interest due to the fact of its abundant raw materials and low cost, and has become the most promising secondary battery. Tunnel-type sodium manganese oxides (TMOs) are industrialized cathode materials because of their simple synthesis method and proficient electrochemical performance. Na0.44MnO2 (NMO) is considered the best candidate material for all tunnel-type structural materials. In this paper, the research progress in charge and discharge of cathode materials for tunnel-type structural SIBs is reviewed, the redox mechanism and all sorts of synthesis methods and different coating methods lead to different morphology and electrochemical properties of materials and the classification of electrolytes and non-aqueous electrolytes. The development and utility of aqueous solutions are discussed, and the mechanism is analyzed. Summarized the cationic potential of the transition metal oxide for tunnel structure, plays a vital role in predicting and designing the cathode material of this structure. In addition, the future opportunities and challenges for such tunnel-type SIBs in this field are described in detail.
Among the large energy storage batteries, the sodium ion batteries (SIBs) are attracted huge interest due to the fact of its abundant raw materials and low cost, and has become the most promising secondary battery. Tunnel-type sodium manganese oxides (TMOs) are industrialized cathode materials because of their simple synthesis method and proficient electrochemical performance. Na0.44MnO2 (NMO) is considered the best candidate material for all tunnel-type structural materials. In this paper, the research progress in charge and discharge of cathode materials for tunnel-type structural SIBs is reviewed, the redox mechanism and all sorts of synthesis methods and different coating methods lead to different morphology and electrochemical properties of materials and the classification of electrolytes and non-aqueous electrolytes. The development and utility of aqueous solutions are discussed, and the mechanism is analyzed. Summarized the cationic potential of the transition metal oxide for tunnel structure, plays a vital role in predicting and designing the cathode material of this structure. In addition, the future opportunities and challenges for such tunnel-type SIBs in this field are described in detail.
2022, 33(5): 2327-2344
doi: 10.1016/j.cclet.2021.12.013
Abstract:
This brief review reports the recent advancement of metallic glasses and metallic glass nanostructures for functional electrocatalytic applications. Metallic glasses (MGs) or amorphous metals result from quenching the melts at a high cooling rate (e.g., 106 K/s), bypassing crystallization. Metallic glasses are devoid of long-range translational order, no defects like grain boundaries, and multiple elements included. Due to these unique structural features, MG's show distinct and valuable mechanical, physical and chemical properties and therefore were widely studied as a structural material for decades. Even though MGs were proposed for catalytic applications earlier, a comprehensive study or attempt to apply these materials successfully in electrocatalytic applications are few since the intrinsic surface area is comparably lesser. A rejuvenated interest among the research community for applying various novel strategies in catalytic applications of MGs is highlighted in the present review. Theoretical approaches using density functional theory (DFT) and high-throughput screening assisted with machine learning paradigm advances the discovery of new MGs, which demonstrated high potential for catalytic applications. We focus on the basic features and recent advances in the MGs for catalytic applications like electrocatalytic water splitting reactions like HER, OER, fuel cell reactions like ORR, alcohol oxidation reactions like MOR, EOR, and degradation of harmful organic dyes from the industrial effluents. The presently advancing strategies for enhancing the performance of these metallic glass electrocatalysts through nanostructuring and high-throughput screening are discussed. The unique atomic-scale structural mechanism of the metallic glasses, which can favor the development of high-performance electrocatalysts even comparable to currently available precious-metal-based catalysts, will be discussed. Finally, we also give future directions on designing novel and superior metallic glass-based advanced catalysts.
This brief review reports the recent advancement of metallic glasses and metallic glass nanostructures for functional electrocatalytic applications. Metallic glasses (MGs) or amorphous metals result from quenching the melts at a high cooling rate (e.g., 106 K/s), bypassing crystallization. Metallic glasses are devoid of long-range translational order, no defects like grain boundaries, and multiple elements included. Due to these unique structural features, MG's show distinct and valuable mechanical, physical and chemical properties and therefore were widely studied as a structural material for decades. Even though MGs were proposed for catalytic applications earlier, a comprehensive study or attempt to apply these materials successfully in electrocatalytic applications are few since the intrinsic surface area is comparably lesser. A rejuvenated interest among the research community for applying various novel strategies in catalytic applications of MGs is highlighted in the present review. Theoretical approaches using density functional theory (DFT) and high-throughput screening assisted with machine learning paradigm advances the discovery of new MGs, which demonstrated high potential for catalytic applications. We focus on the basic features and recent advances in the MGs for catalytic applications like electrocatalytic water splitting reactions like HER, OER, fuel cell reactions like ORR, alcohol oxidation reactions like MOR, EOR, and degradation of harmful organic dyes from the industrial effluents. The presently advancing strategies for enhancing the performance of these metallic glass electrocatalysts through nanostructuring and high-throughput screening are discussed. The unique atomic-scale structural mechanism of the metallic glasses, which can favor the development of high-performance electrocatalysts even comparable to currently available precious-metal-based catalysts, will be discussed. Finally, we also give future directions on designing novel and superior metallic glass-based advanced catalysts.
2022, 33(5): 2345-2353
doi: 10.1016/j.cclet.2021.09.062
Abstract:
Two-dimensional (2D) materials composed of single pnictogen element, namely, 2D pnictogens (e.g., black phosphorus, arsenene, antimonene and bismuthine), have recently showed remarkable potential for biomedical applications, especially after the rapid development of black phosphorus. With unique optical and electronic properties, 2D pnictogens are considered as promising nanoagents for biosensors, diagnosis and therapy. In this review, after brief introduction of the structure, properties, synthesis strategies, and biocompatibility of 2D pnictogens, their biomedical applications including anti-tumor, anti-inflammation, anti-bacterial, neurodegenerative treatment and tissue repairing are reviewed. The major obstacles and opportunities of 2D pnictogens are also discussed. This review provides a short yet timely summary on the synthesis and biomedical applications of emerging 2D pnictogens.
Two-dimensional (2D) materials composed of single pnictogen element, namely, 2D pnictogens (e.g., black phosphorus, arsenene, antimonene and bismuthine), have recently showed remarkable potential for biomedical applications, especially after the rapid development of black phosphorus. With unique optical and electronic properties, 2D pnictogens are considered as promising nanoagents for biosensors, diagnosis and therapy. In this review, after brief introduction of the structure, properties, synthesis strategies, and biocompatibility of 2D pnictogens, their biomedical applications including anti-tumor, anti-inflammation, anti-bacterial, neurodegenerative treatment and tissue repairing are reviewed. The major obstacles and opportunities of 2D pnictogens are also discussed. This review provides a short yet timely summary on the synthesis and biomedical applications of emerging 2D pnictogens.
2022, 33(5): 2354-2362
doi: 10.1016/j.cclet.2021.10.081
Abstract:
Graphene oxide (GO), as a metal-free and readily available carbocatalyst, has been extensively applied in catalytic organic transformations. This minireview aims to give an overview of the progress on the application of native GO as a catalyst for various organic transformations in the past decade (mainly from 2011 to 2020).
Graphene oxide (GO), as a metal-free and readily available carbocatalyst, has been extensively applied in catalytic organic transformations. This minireview aims to give an overview of the progress on the application of native GO as a catalyst for various organic transformations in the past decade (mainly from 2011 to 2020).
2022, 33(5): 2363-2371
doi: 10.1016/j.cclet.2021.11.049
Abstract:
α-(Trifluoromethyl)styrene and its derivatives have found wide applications in the fields of pharmaceuticals, agrochemicals, and advanced materials. They are also versatile trifluoromethyl-containing building blocks for the preparation of various trifluoromethyl-containing, fluorine-containing or nonfluorinated compounds. Recently, great efforts have been made to develop diverse reactions for rapidly accessing a wide range of valuable gem-difluoroalkenes and gem-difluoroalkylated compounds via defluorinative reaction or the defluorinative ipso-functionalization reaction of α-(trifluoromethyl)styrenes, respectively. In contrast, α-(trifluoromethyl)styrenes remain notably underdeveloped with respect to their use in cycloaddition and hydroaddition reaction with retaining of three CF bonds. This short review herein is aimed to summarize the recent progress on the cycloaddition and hydroaddition reaction including nucleophilic, radical and transition metal-catalyzed addition of α-(trifluoromethyl)styrenes without accompanying defluorination.
α-(Trifluoromethyl)styrene and its derivatives have found wide applications in the fields of pharmaceuticals, agrochemicals, and advanced materials. They are also versatile trifluoromethyl-containing building blocks for the preparation of various trifluoromethyl-containing, fluorine-containing or nonfluorinated compounds. Recently, great efforts have been made to develop diverse reactions for rapidly accessing a wide range of valuable gem-difluoroalkenes and gem-difluoroalkylated compounds via defluorinative reaction or the defluorinative ipso-functionalization reaction of α-(trifluoromethyl)styrenes, respectively. In contrast, α-(trifluoromethyl)styrenes remain notably underdeveloped with respect to their use in cycloaddition and hydroaddition reaction with retaining of three CF bonds. This short review herein is aimed to summarize the recent progress on the cycloaddition and hydroaddition reaction including nucleophilic, radical and transition metal-catalyzed addition of α-(trifluoromethyl)styrenes without accompanying defluorination.
2022, 33(5): 2372-2382
doi: 10.1016/j.cclet.2021.11.044
Abstract:
Lewis base-catalyzed annulations of allenoates have been one of the most powerful synthetic strategies for the synthesis of various valuable cycles, especially in the preparation of biologically active natural products and pharmaceuticals. Generally, the effective Lewis bases mainly include tertiary phosphine, NHC and tertiary amine catalysts, among those catalysis, tertiary amine Lewis bases have proven to be effective catalysts for a range of synthetic transformations. In the past decades, tremendous progress involving tertiary amines-promoted cycloaddition of allenoates has been made in the chemoselective construction of valuable motifs. This review describes a comprehensive and updated summary of tertiary amine Lewis base-promoted annulation reactions of allenoates. Diverse reactivities, chemoselectivties and detailed reaction mechanisms will be highlighted in this review.
Lewis base-catalyzed annulations of allenoates have been one of the most powerful synthetic strategies for the synthesis of various valuable cycles, especially in the preparation of biologically active natural products and pharmaceuticals. Generally, the effective Lewis bases mainly include tertiary phosphine, NHC and tertiary amine catalysts, among those catalysis, tertiary amine Lewis bases have proven to be effective catalysts for a range of synthetic transformations. In the past decades, tremendous progress involving tertiary amines-promoted cycloaddition of allenoates has been made in the chemoselective construction of valuable motifs. This review describes a comprehensive and updated summary of tertiary amine Lewis base-promoted annulation reactions of allenoates. Diverse reactivities, chemoselectivties and detailed reaction mechanisms will be highlighted in this review.
2022, 33(5): 2383-2386
doi: 10.1016/j.cclet.2021.11.009
Abstract:
A copper-catalyzed three-component reaction of alkenes, cycloketone oximes and DABCO·(SO2)2 is developed, which provides a convenient route for the synthesis of diverse (E)-cyanoalkylsulfonyl alkenes in moderate to good yields with excellent regio- and stereoselectivity. A broad substrate scope with excellent functional group tolerance is observed. A plausible radical pathway is proposed, which involves copper-catalyzed ring-opening CC bond cleavage of O-acyl oxime and insertion of sulfur dioxide. During the reaction process, cyanoalkyl radical and cyanoalkylsulfonyl radical are the key intermediates.
A copper-catalyzed three-component reaction of alkenes, cycloketone oximes and DABCO·(SO2)2 is developed, which provides a convenient route for the synthesis of diverse (E)-cyanoalkylsulfonyl alkenes in moderate to good yields with excellent regio- and stereoselectivity. A broad substrate scope with excellent functional group tolerance is observed. A plausible radical pathway is proposed, which involves copper-catalyzed ring-opening CC bond cleavage of O-acyl oxime and insertion of sulfur dioxide. During the reaction process, cyanoalkyl radical and cyanoalkylsulfonyl radical are the key intermediates.
2022, 33(5): 2387-2390
doi: 10.1016/j.cclet.2021.11.045
Abstract:
Although fluorobis(phenylsulfonyl)methane (FBSM) and its cyclic analog 2-fluoro-1, 3-benzodithiole-1, 1, 3, 3-tetraoxide (FBDT) possess similar physicochemical properties, Shibata et al. found that FBSM failed to undergo nucleophilic monofluoromethylation of aldehydes regardless of the reaction conditions attempted (using various organic and inorganic bases). However, it was later discovered by Hu et al. that the nucleophilic monofluoromethylation could be accomplished by employing lithium hexamethyldisilazide (LiHMDS) as a base. Herein, we present an in-depth computational investigation into the intriguing effects of reagent structure and bases on the nucleophilic monofluoromethylation of aldehydes. The computations reveal the 1, 4-diazabicyclo[2.2.2]octane (DABCO) catalyzed nucleophilic monofluoromethylation of benzaldehyde with acyclic FBSM is a thermodynamically unfavorable process mainly due to the destabilizing O···O lone pair repulsions in FBSM product, whereas such repulsion could be largely avoided in FBDT product because of its constrained five-membered ring structure. Employing LiHMDS as a base can not only facilitate the nucleophilic monofluoromethylation via Li–O interactions but also render the monofluoromethylation of benzaldehyde with FBSM thermodynamically favored.
Although fluorobis(phenylsulfonyl)methane (FBSM) and its cyclic analog 2-fluoro-1, 3-benzodithiole-1, 1, 3, 3-tetraoxide (FBDT) possess similar physicochemical properties, Shibata et al. found that FBSM failed to undergo nucleophilic monofluoromethylation of aldehydes regardless of the reaction conditions attempted (using various organic and inorganic bases). However, it was later discovered by Hu et al. that the nucleophilic monofluoromethylation could be accomplished by employing lithium hexamethyldisilazide (LiHMDS) as a base. Herein, we present an in-depth computational investigation into the intriguing effects of reagent structure and bases on the nucleophilic monofluoromethylation of aldehydes. The computations reveal the 1, 4-diazabicyclo[2.2.2]octane (DABCO) catalyzed nucleophilic monofluoromethylation of benzaldehyde with acyclic FBSM is a thermodynamically unfavorable process mainly due to the destabilizing O···O lone pair repulsions in FBSM product, whereas such repulsion could be largely avoided in FBDT product because of its constrained five-membered ring structure. Employing LiHMDS as a base can not only facilitate the nucleophilic monofluoromethylation via Li–O interactions but also render the monofluoromethylation of benzaldehyde with FBSM thermodynamically favored.
2022, 33(5): 2391-2396
doi: 10.1016/j.cclet.2021.10.083
Abstract:
Herein, we report an unprecedented regiospecific oxidative Mizoroki-Heck type reaction for the synthesis of α-difluoromethyl homoallylic alcohols. The reaction shows broad substrate scopes and high functional group tolerance. Late-stage functionalization of complex biologically active molecules demonstrates the synthetic potential of this transformation. Mechanistic study supports the involvement of MnBr2 catalyzed radical 1, 2-silyl transfer.
Herein, we report an unprecedented regiospecific oxidative Mizoroki-Heck type reaction for the synthesis of α-difluoromethyl homoallylic alcohols. The reaction shows broad substrate scopes and high functional group tolerance. Late-stage functionalization of complex biologically active molecules demonstrates the synthetic potential of this transformation. Mechanistic study supports the involvement of MnBr2 catalyzed radical 1, 2-silyl transfer.
2022, 33(5): 2397-2401
doi: 10.1016/j.cclet.2021.10.019
Abstract:
A new relay C–H functionalization of di([1, 1′-biphenyl]-2-yl)phosphine oxide to obtain esterified and hydroxylated products with different hypervalent iodines as oxidants under palladium catalysis is disclosed. This reaction provides a more effective and concise strategy for the synthesis of novel structural hybrid-arylcyclophosphorus ligand precursors with a wide range of substrates and good functional group tolerance.
A new relay C–H functionalization of di([1, 1′-biphenyl]-2-yl)phosphine oxide to obtain esterified and hydroxylated products with different hypervalent iodines as oxidants under palladium catalysis is disclosed. This reaction provides a more effective and concise strategy for the synthesis of novel structural hybrid-arylcyclophosphorus ligand precursors with a wide range of substrates and good functional group tolerance.
2022, 33(5): 2402-2406
doi: 10.1016/j.cclet.2021.11.064
Abstract:
Oxygen ligation is envisioned to provide a stable and distinctive coordination environment to the strongly oxophilic rare-earth metals. However, the well-defined dialkyl complexes bearing oxyanion ancillary ligand had been rarely addressed for the instability of the complexes and the shortage of easily available ligands. Herein, we report the synthesis of phosphate ligated dialkyl yttrium complexes (PYR2) featuring a high stability and a tunable ligand. Treated with the borate reagent, the phosphate yttrium complex displays high activity and selectivity in the catalytic cis-1, 4-polymerization of isoprene (up to 96.5%). Furthermore, using AlMe3 as an additive, the stereoselectivity switches to trans-1, 4-polymerization (up to 92.0%).
Oxygen ligation is envisioned to provide a stable and distinctive coordination environment to the strongly oxophilic rare-earth metals. However, the well-defined dialkyl complexes bearing oxyanion ancillary ligand had been rarely addressed for the instability of the complexes and the shortage of easily available ligands. Herein, we report the synthesis of phosphate ligated dialkyl yttrium complexes (PYR2) featuring a high stability and a tunable ligand. Treated with the borate reagent, the phosphate yttrium complex displays high activity and selectivity in the catalytic cis-1, 4-polymerization of isoprene (up to 96.5%). Furthermore, using AlMe3 as an additive, the stereoselectivity switches to trans-1, 4-polymerization (up to 92.0%).
2022, 33(5): 2407-2410
doi: 10.1016/j.cclet.2021.10.020
Abstract:
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmann rearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and imide products in modular procedures. The generality and tolerance of functionalities of this method have been demonstrated.
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmann rearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and imide products in modular procedures. The generality and tolerance of functionalities of this method have been demonstrated.
2022, 33(5): 2411-2414
doi: 10.1016/j.cclet.2021.10.037
Abstract:
The first intermolecular electrophilic dearomatization of halonaphthols with benzyl/allyl bromides is described. Halonaphthols are used as carbon-nucleophiles in dearomatization to form three-dimensional cyclic enones with excellent chemoselectivity, in which etherification of phenolic hydroxyl group could be restrained well by using cesium carbonate as the base. A wide range of cyclic enones is directly prepared from various substituted benzyl/allyl bromides and halonaphthols. Mechanistic investigations suggest a direct SN2 reaction pathway.
The first intermolecular electrophilic dearomatization of halonaphthols with benzyl/allyl bromides is described. Halonaphthols are used as carbon-nucleophiles in dearomatization to form three-dimensional cyclic enones with excellent chemoselectivity, in which etherification of phenolic hydroxyl group could be restrained well by using cesium carbonate as the base. A wide range of cyclic enones is directly prepared from various substituted benzyl/allyl bromides and halonaphthols. Mechanistic investigations suggest a direct SN2 reaction pathway.
2022, 33(5): 2415-2419
doi: 10.1016/j.cclet.2021.10.062
Abstract:
A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies (up to > 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF3-β-disubstituted nitroalkene was favorable.
A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies (up to > 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF3-β-disubstituted nitroalkene was favorable.
2022, 33(5): 2420-2424
doi: 10.1016/j.cclet.2021.11.023
Abstract:
The tandem reaction of photoinduced double hydrogen-atom transfer and deoxygenative transborylation for chemo- and site-selective reduction of nitroarenes into aryl amines under catalyst-free, room temperature conditions was disclosed in excellent yields. In this reaction, isopropanol (iPrOH) was used as hydrogen donor and tetrahydroxydiboron [B2(OH)4] as deoxygenative reagent with green, cheap, and commercially available credentials. In particular, a wide range of reducible functional groups such as halogen (-Cl, -Br and even -I), alkenyl, alkynyl, aldehyde, ketone, carboxyl, and cyano are all tolerated. Moreover, the reaction preferentially reduces the nitro group at the electron-deficient site over another nitro group in the same molecule. A detailed mechanistic investigation in combination of experiments and theoretical calculations gave a reasonable explanation for the reaction pathway.
The tandem reaction of photoinduced double hydrogen-atom transfer and deoxygenative transborylation for chemo- and site-selective reduction of nitroarenes into aryl amines under catalyst-free, room temperature conditions was disclosed in excellent yields. In this reaction, isopropanol (iPrOH) was used as hydrogen donor and tetrahydroxydiboron [B2(OH)4] as deoxygenative reagent with green, cheap, and commercially available credentials. In particular, a wide range of reducible functional groups such as halogen (-Cl, -Br and even -I), alkenyl, alkynyl, aldehyde, ketone, carboxyl, and cyano are all tolerated. Moreover, the reaction preferentially reduces the nitro group at the electron-deficient site over another nitro group in the same molecule. A detailed mechanistic investigation in combination of experiments and theoretical calculations gave a reasonable explanation for the reaction pathway.
2022, 33(5): 2425-2428
doi: 10.1016/j.cclet.2021.09.092
Abstract:
We report the convenient synthesis of a benzobis(imidazolium)-embedded conjugated polyelectrolyte pBBI by a Cu-catalyzed direct C‒H arylation of a cationic benzobis(imidazolium) monomer with a diiodide comonomer. pBBI shows weak fluorescence in solution due to rotation of the repeat units in the conjugated backbone, and enhanced fluorescence when electrostatically interacting with a variety of anions to form aggregates. Specially, pBBI responds to the bisulfite anion with intensified unique deep-blue fluorescence easily discriminated by naked eye.
We report the convenient synthesis of a benzobis(imidazolium)-embedded conjugated polyelectrolyte pBBI by a Cu-catalyzed direct C‒H arylation of a cationic benzobis(imidazolium) monomer with a diiodide comonomer. pBBI shows weak fluorescence in solution due to rotation of the repeat units in the conjugated backbone, and enhanced fluorescence when electrostatically interacting with a variety of anions to form aggregates. Specially, pBBI responds to the bisulfite anion with intensified unique deep-blue fluorescence easily discriminated by naked eye.
2022, 33(5): 2429-2432
doi: 10.1016/j.cclet.2021.10.066
Abstract:
An efficient chlorination reaction of in situ generated (β-diazo-α, α-difluoroethyl)phosphonates has been achieved with hydrochloric acid as a chlorine source under mild and operationally convenient conditions. The reaction does not need any catalyst and tolerates a wide scope of substrates, which affords the (β-chlorodifluoroethyl)phosphonate products in good to excellent yields. This reaction represents the first example of the halogenation of difluoroalkyl diazo compounds, and also provides an easy way for the synthesis of difluoromethylenephosphonate-containing compounds.
An efficient chlorination reaction of in situ generated (β-diazo-α, α-difluoroethyl)phosphonates has been achieved with hydrochloric acid as a chlorine source under mild and operationally convenient conditions. The reaction does not need any catalyst and tolerates a wide scope of substrates, which affords the (β-chlorodifluoroethyl)phosphonate products in good to excellent yields. This reaction represents the first example of the halogenation of difluoroalkyl diazo compounds, and also provides an easy way for the synthesis of difluoromethylenephosphonate-containing compounds.
2022, 33(5): 2433-2436
doi: 10.1016/j.cclet.2021.10.067
Abstract:
The first total synthesis of dracaenins A and B is achieved in four steps. The synthesis features the convergent coupling of three readily available fragments with minimized use of protecting groups. The chemical synthesis enables the discovery of their activity in stimulating platelet aggregation, and thus, sheds light on the possible origin of the hemostatic effect of dragon's blood.
The first total synthesis of dracaenins A and B is achieved in four steps. The synthesis features the convergent coupling of three readily available fragments with minimized use of protecting groups. The chemical synthesis enables the discovery of their activity in stimulating platelet aggregation, and thus, sheds light on the possible origin of the hemostatic effect of dragon's blood.
2022, 33(5): 2437-2441
doi: 10.1016/j.cclet.2021.11.067
Abstract:
The asymmetric carbenoid CH insertion of 3-diazooxindoles into 1, 4-cyclohexadiene has been accomplished in the presence of chiral bis(imidazoline) NCN pincer iridium(Ⅲ) complexes as the catalysts. With a catalyst loading of 0.5 mol%, the reactions proceeded smoothly at 0 ℃ to afford a variety of chiral 3-substituted oxindoles in good yields with moderate to excellent enantioselectivities (up to 99% ee). The protocol exhibits good functional group tolerance with respect to 3-diazooxindoles and is readily scaled up to 2 mmol scale without any loss in activity and enantioselectivity. Density functional theory (DFT) calculations have been performed to better understand the reaction mechanism and to explain the stereochemical outcome of the reactions.
The asymmetric carbenoid CH insertion of 3-diazooxindoles into 1, 4-cyclohexadiene has been accomplished in the presence of chiral bis(imidazoline) NCN pincer iridium(Ⅲ) complexes as the catalysts. With a catalyst loading of 0.5 mol%, the reactions proceeded smoothly at 0 ℃ to afford a variety of chiral 3-substituted oxindoles in good yields with moderate to excellent enantioselectivities (up to 99% ee). The protocol exhibits good functional group tolerance with respect to 3-diazooxindoles and is readily scaled up to 2 mmol scale without any loss in activity and enantioselectivity. Density functional theory (DFT) calculations have been performed to better understand the reaction mechanism and to explain the stereochemical outcome of the reactions.
2022, 33(5): 2442-2446
doi: 10.1016/j.cclet.2021.10.050
Abstract:
Perylene derivative with circularly polarized luminescence (CPL) at aggregated state was seldom reported due to the strong ACQ (aggregation-caused quench) effect at aggregation. In this work, a novel cholesterol-tetraphenylethylene-perylene derivative (TPE-P) was designed and synthesized in moderate yield. It exhibited liquid crystalline behavior with orderly hexagonal columnar mesophase and good fluorescence emission at long wavelength (600-700 nm) not only in solution but also at aggregated states based on the AIE (aggregation-induced emission)-FRET (fluorescence resonance energy transfer) effect between tetraphenylethylene unit and perylene moiety. Moreover, the circular dichroism (CD) and CPL studies suggested the effective chiral transfer from cholesterol unit to tetraphenylethylene unit and perylene skeleton due to the spiral liquid crystalline self-assembly. The CD and CPL signals showed the order of THF < THF-hexane < solid film < meosphase, indicating that the higher spiral orderly degree resulted in the stronger chiral transfer. The largest |glum| value for mesophase excited at 320 nm was as high as 1.5×10−2 based on the combining effect of AIE-FRET and chiral transfer. This research not only reported a novel CPL perylene derivative at aggregated state, but also confirmed that the combination of AIE-FRET effect and chiral transfer of liquid crytalline phase was an effective method to construct normal dye with excellent CPL property in aggregated state.
Perylene derivative with circularly polarized luminescence (CPL) at aggregated state was seldom reported due to the strong ACQ (aggregation-caused quench) effect at aggregation. In this work, a novel cholesterol-tetraphenylethylene-perylene derivative (TPE-P) was designed and synthesized in moderate yield. It exhibited liquid crystalline behavior with orderly hexagonal columnar mesophase and good fluorescence emission at long wavelength (600-700 nm) not only in solution but also at aggregated states based on the AIE (aggregation-induced emission)-FRET (fluorescence resonance energy transfer) effect between tetraphenylethylene unit and perylene moiety. Moreover, the circular dichroism (CD) and CPL studies suggested the effective chiral transfer from cholesterol unit to tetraphenylethylene unit and perylene skeleton due to the spiral liquid crystalline self-assembly. The CD and CPL signals showed the order of THF < THF-hexane < solid film < meosphase, indicating that the higher spiral orderly degree resulted in the stronger chiral transfer. The largest |glum| value for mesophase excited at 320 nm was as high as 1.5×10−2 based on the combining effect of AIE-FRET and chiral transfer. This research not only reported a novel CPL perylene derivative at aggregated state, but also confirmed that the combination of AIE-FRET effect and chiral transfer of liquid crytalline phase was an effective method to construct normal dye with excellent CPL property in aggregated state.
2022, 33(5): 2447-2450
doi: 10.1016/j.cclet.2021.09.106
Abstract:
Conformational regulation among two or more distant sites is not only one of the main pathways to accomplish multiple tasks in complex biological systems but also represents a powerful strategy to obtain stimuli-responsive supramolecular nanoconstructs with tailored physicochemical performance. We herein report the fabrication of a photochromic supramolecular assembly, which can be synergistically activated by the conformational regulation with bis(4, 8-disulfonato-1, 5-naphtho)-32-crown-8 and then reversibly switched by the through-space communication between restricted stilbazolium salt and photochromic dithienylethene. This work demonstrates that the synergistic conformational modulation via intra- and intermolecular interactions can be developed as a generalizable approach to construct more advanced biomimetic nanomaterials.
Conformational regulation among two or more distant sites is not only one of the main pathways to accomplish multiple tasks in complex biological systems but also represents a powerful strategy to obtain stimuli-responsive supramolecular nanoconstructs with tailored physicochemical performance. We herein report the fabrication of a photochromic supramolecular assembly, which can be synergistically activated by the conformational regulation with bis(4, 8-disulfonato-1, 5-naphtho)-32-crown-8 and then reversibly switched by the through-space communication between restricted stilbazolium salt and photochromic dithienylethene. This work demonstrates that the synergistic conformational modulation via intra- and intermolecular interactions can be developed as a generalizable approach to construct more advanced biomimetic nanomaterials.
2022, 33(5): 2451-2454
doi: 10.1016/j.cclet.2021.09.096
Abstract:
Reported here is the comprehensive investigation on the formation of biphen[n]arenes by tailoring reaction modules. Five new macrocyclic arenes and four oligomers were synthesized by the condensation of monomers possessing different multimethoxyphenyl reaction modules and paraformaldehyde. We proved that the number and sites of methoxy on reaction modules greatly affected the reaction activity, shape, and connection mode of macrocycles. Moreover, the triangular and saddle-shaped configuration of macrocycles were revealed by single crystal structures. The results provided a typical and fundamental guidance in designing new macrocyclic arenes.
Reported here is the comprehensive investigation on the formation of biphen[n]arenes by tailoring reaction modules. Five new macrocyclic arenes and four oligomers were synthesized by the condensation of monomers possessing different multimethoxyphenyl reaction modules and paraformaldehyde. We proved that the number and sites of methoxy on reaction modules greatly affected the reaction activity, shape, and connection mode of macrocycles. Moreover, the triangular and saddle-shaped configuration of macrocycles were revealed by single crystal structures. The results provided a typical and fundamental guidance in designing new macrocyclic arenes.
2022, 33(5): 2455-2458
doi: 10.1016/j.cclet.2021.11.053
Abstract:
A linear supramolecular polymer with controllable features based on twisted cucurbit[14]uril (tQ[14]) and cucurbit[8]uril (Q[8]) was firstly fabricated via an effective self-sorting strategy. Herein we designed a monomer, 1-butyl-1′-(naphthalen- 2-ylmethyl)-4, 4′-bipyridinium bromide (BNB), that contains bipyridyl, aliphatic butyl and aromatic naphthyl groups, simultaneously. Two host molecules, tQ[14] and Q[8] were employed to develop an effective strategy for constructing a linear supramolecular polymer with controllable features. The alkyl groups on both sides of BNB could insert into the two cavities of tQ[14], the naphthyl part of BNB via π-π stacking in Q[8] cavity, serving as the driving force for supramolecular polymerization. Through self-sorting of the monomer, tQ[14] and Q[8], led to the formation of the linear supramolecular polymer. Depolymerization could be achieved by addition of adamantane hydrochloride (AH) which driven two BNB guest molecules out of the Q[8] cavity. This self-sorting strategy has great potential, not only for designing supramolecular polymer materials with different controllable structures through introduction of multiple functional groups, but also for broadening the application of twisted cucurbit[14]uril in supramolecular chemistry.
A linear supramolecular polymer with controllable features based on twisted cucurbit[14]uril (tQ[14]) and cucurbit[8]uril (Q[8]) was firstly fabricated via an effective self-sorting strategy. Herein we designed a monomer, 1-butyl-1′-(naphthalen- 2-ylmethyl)-4, 4′-bipyridinium bromide (BNB), that contains bipyridyl, aliphatic butyl and aromatic naphthyl groups, simultaneously. Two host molecules, tQ[14] and Q[8] were employed to develop an effective strategy for constructing a linear supramolecular polymer with controllable features. The alkyl groups on both sides of BNB could insert into the two cavities of tQ[14], the naphthyl part of BNB via π-π stacking in Q[8] cavity, serving as the driving force for supramolecular polymerization. Through self-sorting of the monomer, tQ[14] and Q[8], led to the formation of the linear supramolecular polymer. Depolymerization could be achieved by addition of adamantane hydrochloride (AH) which driven two BNB guest molecules out of the Q[8] cavity. This self-sorting strategy has great potential, not only for designing supramolecular polymer materials with different controllable structures through introduction of multiple functional groups, but also for broadening the application of twisted cucurbit[14]uril in supramolecular chemistry.
2022, 33(5): 2459-2463
doi: 10.1016/j.cclet.2021.11.010
Abstract:
Detection of nucleoside derivatives has paramount importance because they are the essential biomolecular units for all life. Herein, we report a host-guest approach by using a fluorescent tetraphenylethene-based octacationic cage as host and 8-hydroxypyrene-1, 3, 6-trisulfonic acid trisodium salt (HPTS) as guest and fluorescent indicator to form non-fluorescent 1:1:1 host-(endo-exo)guest complex in water. This new host-(endo-exo)guest complex can be successfully used for detecting nucleosides (e.g., ATP and GTP), DNA (e.g., sm-DNA), and antibiotics (e.g., Penicillin G) with off-on fluorescence response via a competitive host-guest exchange with HPTS as exo-guest in water. Furthermore, this on-off-on fluorescent host-guest complex is also used for cell imaging based on ATP concentration in HeLa cells. Therefore, this study not only provides insight into the construction of a supramolecular probe with on-off-on fluorescence via host-guest complexation and exchange in solution, but also realizes a universal method for detecting and monitoring biomolecules.
Detection of nucleoside derivatives has paramount importance because they are the essential biomolecular units for all life. Herein, we report a host-guest approach by using a fluorescent tetraphenylethene-based octacationic cage as host and 8-hydroxypyrene-1, 3, 6-trisulfonic acid trisodium salt (HPTS) as guest and fluorescent indicator to form non-fluorescent 1:1:1 host-(endo-exo)guest complex in water. This new host-(endo-exo)guest complex can be successfully used for detecting nucleosides (e.g., ATP and GTP), DNA (e.g., sm-DNA), and antibiotics (e.g., Penicillin G) with off-on fluorescence response via a competitive host-guest exchange with HPTS as exo-guest in water. Furthermore, this on-off-on fluorescent host-guest complex is also used for cell imaging based on ATP concentration in HeLa cells. Therefore, this study not only provides insight into the construction of a supramolecular probe with on-off-on fluorescence via host-guest complexation and exchange in solution, but also realizes a universal method for detecting and monitoring biomolecules.
2022, 33(5): 2464-2468
doi: 10.1016/j.cclet.2021.11.066
Abstract:
Covalent organic frameworks (COFs), as a novel class of functional polymers, exhibit versatile applications due to their crystalline porous structures and conjugated skeletons. However, synthesis of COFs with high crystallinity still faces great challenges, especially for scale-up preparation. Herein we report a two-step solvothermal process to improve crystallinity of COFs. The first step focuses on polycondensation of monomers with no need for optimizing crystallization conditions. In the second step, appropriate solvothermal conditions are used to facilitate crystallization of the COFs through defects correction and structural repairing. Furthermore, this strategy could also be applicable to scale-up synthesis of high quality COFs, which lays a foundation for their practical applications.
Covalent organic frameworks (COFs), as a novel class of functional polymers, exhibit versatile applications due to their crystalline porous structures and conjugated skeletons. However, synthesis of COFs with high crystallinity still faces great challenges, especially for scale-up preparation. Herein we report a two-step solvothermal process to improve crystallinity of COFs. The first step focuses on polycondensation of monomers with no need for optimizing crystallization conditions. In the second step, appropriate solvothermal conditions are used to facilitate crystallization of the COFs through defects correction and structural repairing. Furthermore, this strategy could also be applicable to scale-up synthesis of high quality COFs, which lays a foundation for their practical applications.
2022, 33(5): 2469-2472
doi: 10.1016/j.cclet.2021.12.005
Abstract:
A novel fluorescent sensor was prepared from sulfonated calix[4]arene (SC4A) by the host-guest complexation method using the fluorescent dye rhodamine B (RB) as a structure-directing agent. The crystal structure of the host-guest complex (RB@(SC4A)3) was confirmed by X-ray diffraction studies while its performance and sensing mechanism for metal ion pollutants were characterized using fluorescence and nuclear magnetic resonance spectroscopies. The results showed that RB@(SC4A)3 had a triangular branch structure resulting from host-guest mediation of the interactions between the three SC4A host molecules and the three terminal groups of the guest molecule RB. The host-guest complex exhibited sensitive and selective sensing towards Fe3+ ions via a fluorescence quenching mechanism. The results indicated that RB@(SC4A)3 could be a promising sensitive and selective fluorescent sensor for metal ion pollutants monitoring. It also provided new insights into the synthesis of calixarene-based host-guest complex.
A novel fluorescent sensor was prepared from sulfonated calix[4]arene (SC4A) by the host-guest complexation method using the fluorescent dye rhodamine B (RB) as a structure-directing agent. The crystal structure of the host-guest complex (RB@(SC4A)3) was confirmed by X-ray diffraction studies while its performance and sensing mechanism for metal ion pollutants were characterized using fluorescence and nuclear magnetic resonance spectroscopies. The results showed that RB@(SC4A)3 had a triangular branch structure resulting from host-guest mediation of the interactions between the three SC4A host molecules and the three terminal groups of the guest molecule RB. The host-guest complex exhibited sensitive and selective sensing towards Fe3+ ions via a fluorescence quenching mechanism. The results indicated that RB@(SC4A)3 could be a promising sensitive and selective fluorescent sensor for metal ion pollutants monitoring. It also provided new insights into the synthesis of calixarene-based host-guest complex.
2022, 33(5): 2473-2476
doi: 10.1016/j.cclet.2021.11.069
Abstract:
Aggregation-induced emission enhancement and aggregation-induced chirality inversion are two individual phenomena for the enantiomerically pure organic dyes in the aggregates. Herein we reported for the first time that these two interesting phenomena could be observed simultaneously in the aggregated states of enantiomerically pure S/R-1, 1′-binaphthol annulated perylene diimides, in which two perylene diimides moieties were bridged by S/R-1, 1′-binaphthol (BINOL) at the bay positions. Owing to the rotatable C2 axes between two naphthol annulated perylene diimides moieties, both of them display intrinsic behaviors of aggregation-induced emission enhancements. At the same time, due to the steric hindrances in the imide and methoxy positions, the neighboring two π-systems of these two unique polycyclic aromatic imides in poor solvents are preferable to adopt a cross-stacking mode and thus form helical X-aggregates of opposite chirality (M/P) with chirality inversion characteristics in their circular dichroism and circularly polarized luminescence spectroscopic studies.
Aggregation-induced emission enhancement and aggregation-induced chirality inversion are two individual phenomena for the enantiomerically pure organic dyes in the aggregates. Herein we reported for the first time that these two interesting phenomena could be observed simultaneously in the aggregated states of enantiomerically pure S/R-1, 1′-binaphthol annulated perylene diimides, in which two perylene diimides moieties were bridged by S/R-1, 1′-binaphthol (BINOL) at the bay positions. Owing to the rotatable C2 axes between two naphthol annulated perylene diimides moieties, both of them display intrinsic behaviors of aggregation-induced emission enhancements. At the same time, due to the steric hindrances in the imide and methoxy positions, the neighboring two π-systems of these two unique polycyclic aromatic imides in poor solvents are preferable to adopt a cross-stacking mode and thus form helical X-aggregates of opposite chirality (M/P) with chirality inversion characteristics in their circular dichroism and circularly polarized luminescence spectroscopic studies.
2022, 33(5): 2477-2480
doi: 10.1016/j.cclet.2021.11.014
Abstract:
Low-valence transition metallic complexes have drawn longstanding attention due to their high reactivity toward catalytic transformation of various small molecules. Among these known complexes, the low-valence metal centres are commonly stabilized by neutral bulky ligands with strong electron-donating capacity. However, low-valence bimetallic complexes supported by anionic sulfur and cyclopentadienyl ligands are still difficult to obtain in high isolated yield. Herein, we report the synthesis and characterization of two scarce thiolate-bridged CoⅠCoⅡ and CoⅠCoⅠ complexes bearing sterically demanding ligands through two stepwise one-electron reduction processes. Interestingly, the CoⅠCoⅡ complex can facilely promote the homolytic cleavage of dihydrogen across the short Co−Co metallic bond to give a CoⅡCoⅢ dihydride bridged complex, which is capable of serving as a competent hydrogen atom transfer agent. Moreover, the anionic CoⅠCoⅠ complex can trigger a stepwise hydrogen generation cycle involving several isolated and structurally well-characterized intermediates.
Low-valence transition metallic complexes have drawn longstanding attention due to their high reactivity toward catalytic transformation of various small molecules. Among these known complexes, the low-valence metal centres are commonly stabilized by neutral bulky ligands with strong electron-donating capacity. However, low-valence bimetallic complexes supported by anionic sulfur and cyclopentadienyl ligands are still difficult to obtain in high isolated yield. Herein, we report the synthesis and characterization of two scarce thiolate-bridged CoⅠCoⅡ and CoⅠCoⅠ complexes bearing sterically demanding ligands through two stepwise one-electron reduction processes. Interestingly, the CoⅠCoⅡ complex can facilely promote the homolytic cleavage of dihydrogen across the short Co−Co metallic bond to give a CoⅡCoⅢ dihydride bridged complex, which is capable of serving as a competent hydrogen atom transfer agent. Moreover, the anionic CoⅠCoⅠ complex can trigger a stepwise hydrogen generation cycle involving several isolated and structurally well-characterized intermediates.
2022, 33(5): 2481-2485
doi: 10.1016/j.cclet.2021.11.083
Abstract:
Self-assembly is a powerful approach in molecular engineering for biomedical applications, in particular for creating self-assembling prodrugs. Here, we report a self-assembling prodrug of the anticancer drug gemcitabine (Gem) based on amphiphilic dendrimer approach. The prodrug reported in this study demonstrates high drug loading (40%) and robust ability to self-assemble into small nanomicelles, which increase the metabolic stability of Gem and enable entry into cells via endocytosis, hence bypassing transport-mediated uptake. In addition, this prodrug nanosystem exhibited an effective pH- and enzyme-responsive release of Gem, resulting in enhanced anticancer activity and reduced toxicity. Harboring advantageous features of both prodrug- and nanotechnology-based drug delivery, this self-assembling Gem prodrug nanosystem constitutes a promising anticancer candidate. This study also offers new perspectives of the amphiphilic dendrimer nanoplatforms for the development of self-assembling prodrugs.
Self-assembly is a powerful approach in molecular engineering for biomedical applications, in particular for creating self-assembling prodrugs. Here, we report a self-assembling prodrug of the anticancer drug gemcitabine (Gem) based on amphiphilic dendrimer approach. The prodrug reported in this study demonstrates high drug loading (40%) and robust ability to self-assemble into small nanomicelles, which increase the metabolic stability of Gem and enable entry into cells via endocytosis, hence bypassing transport-mediated uptake. In addition, this prodrug nanosystem exhibited an effective pH- and enzyme-responsive release of Gem, resulting in enhanced anticancer activity and reduced toxicity. Harboring advantageous features of both prodrug- and nanotechnology-based drug delivery, this self-assembling Gem prodrug nanosystem constitutes a promising anticancer candidate. This study also offers new perspectives of the amphiphilic dendrimer nanoplatforms for the development of self-assembling prodrugs.
An injectable mPEG-PDLLA microsphere/PDLLA-PEG-PDLLA hydrogel composite for soft tissue augmentation
2022, 33(5): 2486-2490
doi: 10.1016/j.cclet.2021.12.093
Abstract:
Injectable filling material is a simple and efficient method for soft tissues reconstruction and is extremely popular in not only plastic surgery but also cosmetic industry. However, there is a lack of soft tissue fillers with perfect performance on the market currently. Here, we constructed a new microsphere/hydrogel composite and evaluated its potential as a candidate for soft tissue augmentation. mPEG-PDLLA microspheres were prepared by utilizing a SPG membrane emulsifier which endowed microspheres with good sphericity and particle size uniformity. PDLLA-PEG-PDLLA hydrogel which shared the same component with the mPEG-PDLLA copolymer acted as a carrier and fixed the microspheres at the injected sites. The mPEG-PDLLA microsphere/PDLLA-PEG-PDLLA hydrogel composite was flowable in room temperature and transformed into gel after being heated to body temperature. This feature is convenient for subcutaneous filling. In vivo assessment on mice showed good safety profile of the composite. Moreover, the density of collagen fibers increased over 13 weeks. Overall, this biocompatible microsphere/hydrogel composite involves simple component and no extra crosslinking agents, and has the ability to stimulate collagen production, thus, may be a candidate for soft tissue augmentation.
Injectable filling material is a simple and efficient method for soft tissues reconstruction and is extremely popular in not only plastic surgery but also cosmetic industry. However, there is a lack of soft tissue fillers with perfect performance on the market currently. Here, we constructed a new microsphere/hydrogel composite and evaluated its potential as a candidate for soft tissue augmentation. mPEG-PDLLA microspheres were prepared by utilizing a SPG membrane emulsifier which endowed microspheres with good sphericity and particle size uniformity. PDLLA-PEG-PDLLA hydrogel which shared the same component with the mPEG-PDLLA copolymer acted as a carrier and fixed the microspheres at the injected sites. The mPEG-PDLLA microsphere/PDLLA-PEG-PDLLA hydrogel composite was flowable in room temperature and transformed into gel after being heated to body temperature. This feature is convenient for subcutaneous filling. In vivo assessment on mice showed good safety profile of the composite. Moreover, the density of collagen fibers increased over 13 weeks. Overall, this biocompatible microsphere/hydrogel composite involves simple component and no extra crosslinking agents, and has the ability to stimulate collagen production, thus, may be a candidate for soft tissue augmentation.
2022, 33(5): 2491-2495
doi: 10.1016/j.cclet.2021.11.038
Abstract:
Gold nanorods (AuNRs), as relatively common materials used in biomedical areas, have been synthesized by means of many methods. However, the conventional seed-mediated method is limited by complex operations and low yield. Besides, for further applications of AuNRs, well monodispersed AuNRs and tunable longitudinal surface plasmon resonance (LSPR) remain to be improved. Herein, we report a one-pot method for synthesizing AuNRs without seeding agents. In this method, we use phenols as reducing agents and hydrochloric acid and nitric acid are used to regulate the pH of the growth solution. AuNRs with the longest LSPR peak position reaching 1340 nm are prepared. Furthermore, by systematically optimizing concentrations of the reagents involved in the growth solution, different aspect ratios of AuNRs are synthesized. The facile synthesis, controllability aspect ratio, and long LSPR peak make our method promising for wider applications of AuNRs.
Gold nanorods (AuNRs), as relatively common materials used in biomedical areas, have been synthesized by means of many methods. However, the conventional seed-mediated method is limited by complex operations and low yield. Besides, for further applications of AuNRs, well monodispersed AuNRs and tunable longitudinal surface plasmon resonance (LSPR) remain to be improved. Herein, we report a one-pot method for synthesizing AuNRs without seeding agents. In this method, we use phenols as reducing agents and hydrochloric acid and nitric acid are used to regulate the pH of the growth solution. AuNRs with the longest LSPR peak position reaching 1340 nm are prepared. Furthermore, by systematically optimizing concentrations of the reagents involved in the growth solution, different aspect ratios of AuNRs are synthesized. The facile synthesis, controllability aspect ratio, and long LSPR peak make our method promising for wider applications of AuNRs.
2022, 33(5): 2496-2500
doi: 10.1016/j.cclet.2021.11.078
Abstract:
Prostate cancer (PCa) is the second most commonly diagnosed cancer in men. The Rac1-GTP inhibitor NSC23766 has been shown to suppress PCa growth. However, these therapies have low tumor-targeting efficacy in vivo. Therefore, it is essential to produce a drug delivery system that specifically targets the tumor site. Herein, novel l-phenylalanine-based poly(ester amide) (Phe-PEA) polymers were synthesized and loaded with NSC23766 (NSC23766@8P6 NPs), which had a small particle size (162.3 ± 6.7 nm) and high NSC23766 loading (8.0% ± 1.1%) with a more rapid release of NSC23766 at pH 5.0. In vitro cellular uptake and cytotoxicity assays demonstrated that NSC23766@8P6 NPs were rapidly taken up by PC3 cells and showed significant effects of PCa cell proliferation inhibition and G2/M phase arrest. Furthermore, in vivo studies using PC3-bearing mice demonstrated that NSC23766@8P6 NPs delivered by intravenous injection not only increased the drug concentration with prolonged retention (96 h) at the tumor site, but also inhibited tumor growth and induced apoptosis. In conclusion, we have discovered that NSC23766@8P6 NPs can serve as a delivery system that targets the tumor site and is therefore a promising therapeutic approach for PCa treatment.
Prostate cancer (PCa) is the second most commonly diagnosed cancer in men. The Rac1-GTP inhibitor NSC23766 has been shown to suppress PCa growth. However, these therapies have low tumor-targeting efficacy in vivo. Therefore, it is essential to produce a drug delivery system that specifically targets the tumor site. Herein, novel l-phenylalanine-based poly(ester amide) (Phe-PEA) polymers were synthesized and loaded with NSC23766 (NSC23766@8P6 NPs), which had a small particle size (162.3 ± 6.7 nm) and high NSC23766 loading (8.0% ± 1.1%) with a more rapid release of NSC23766 at pH 5.0. In vitro cellular uptake and cytotoxicity assays demonstrated that NSC23766@8P6 NPs were rapidly taken up by PC3 cells and showed significant effects of PCa cell proliferation inhibition and G2/M phase arrest. Furthermore, in vivo studies using PC3-bearing mice demonstrated that NSC23766@8P6 NPs delivered by intravenous injection not only increased the drug concentration with prolonged retention (96 h) at the tumor site, but also inhibited tumor growth and induced apoptosis. In conclusion, we have discovered that NSC23766@8P6 NPs can serve as a delivery system that targets the tumor site and is therefore a promising therapeutic approach for PCa treatment.
2022, 33(5): 2501-2506
doi: 10.1016/j.cclet.2021.11.079
Abstract:
The small molecular second near-infrared (NIR-Ⅱ, 1000-1700 nm) dye-based nanotheranostics can concurrently combine deep-tissue photodiagnosis with in situ phototherapy, which occupies a vital position in the early detection and precise treatment of tumors. However, the development of small molecular NIR-Ⅱ dyes is still challenging due to the limited electron acceptors and cumbersome synthetic routes. Herein, we report a novel molecular electron acceptor, boron difluoride formazanate (BDF). Based on BDF, a new small molecular NIR-Ⅱ dye BDF1005 is designed and synthesized with strong NIR-Ⅰ absorption at 768 nm and bright NIR-Ⅱ peak emission at 1034 nm. In vitro and in vivo experiments demonstrate that BDF1005-based nanotheranostics can be applied for NIR-Ⅱ fluorescence imaging-guided photothermal therapy of 4T1 tumor-bearing mice. Under 808 nm laser irradiation, tumor growth can be effectively inhibited. This work opens up a new road for the exploitation of NIR-Ⅱ small molecular dyes for cancer phototheranostics.
The small molecular second near-infrared (NIR-Ⅱ, 1000-1700 nm) dye-based nanotheranostics can concurrently combine deep-tissue photodiagnosis with in situ phototherapy, which occupies a vital position in the early detection and precise treatment of tumors. However, the development of small molecular NIR-Ⅱ dyes is still challenging due to the limited electron acceptors and cumbersome synthetic routes. Herein, we report a novel molecular electron acceptor, boron difluoride formazanate (BDF). Based on BDF, a new small molecular NIR-Ⅱ dye BDF1005 is designed and synthesized with strong NIR-Ⅰ absorption at 768 nm and bright NIR-Ⅱ peak emission at 1034 nm. In vitro and in vivo experiments demonstrate that BDF1005-based nanotheranostics can be applied for NIR-Ⅱ fluorescence imaging-guided photothermal therapy of 4T1 tumor-bearing mice. Under 808 nm laser irradiation, tumor growth can be effectively inhibited. This work opens up a new road for the exploitation of NIR-Ⅱ small molecular dyes for cancer phototheranostics.
2022, 33(5): 2507-2511
doi: 10.1016/j.cclet.2021.11.076
Abstract:
Lung cancer is the most common malignancy in the world, with a high mortality rate. Nevertheless, therapies to act effectively against lung cancer remain elusive. So far, chemotherapy is still the frontline treatment of lung cancer. Doxorubicin (DOX) is a broad-spectrum anti-tumor drug. However, DOX often has serious side effects and causes multi-drug resistance, which greatly limits its clinical application. In this work, biodegradable methoxy poly(ethylene glycol)-poly(lactic acid) (MPEG-PLA) and cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) polypeptide modified PEG-PLA (cRGD-PEG-PLA) copolymers were used for the co-delivery of curcumin (CUR) and DOX (CUR-DOX/cRGD-M). The particle size of the self-assembled drug-loaded nanomicelle approximately was 27.4 nm and the zeta potential was −2.7 mV. Interestingly, CUR can enhance the uptake of DOX by Lewis lung carcinoma (LL/2) cells. The experimental results in vivo and in vitro showed that CUR-DOX/cRGD-M combination therapy could promote apoptosis of lung cancer cells, and conspicuously inhibit the tumor growth. Our data indicate that CUR-DOX/cRGD-M will be biodegradable and sustainable, which may have potential clinical application value in the treatment of lung cancer.
Lung cancer is the most common malignancy in the world, with a high mortality rate. Nevertheless, therapies to act effectively against lung cancer remain elusive. So far, chemotherapy is still the frontline treatment of lung cancer. Doxorubicin (DOX) is a broad-spectrum anti-tumor drug. However, DOX often has serious side effects and causes multi-drug resistance, which greatly limits its clinical application. In this work, biodegradable methoxy poly(ethylene glycol)-poly(lactic acid) (MPEG-PLA) and cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) polypeptide modified PEG-PLA (cRGD-PEG-PLA) copolymers were used for the co-delivery of curcumin (CUR) and DOX (CUR-DOX/cRGD-M). The particle size of the self-assembled drug-loaded nanomicelle approximately was 27.4 nm and the zeta potential was −2.7 mV. Interestingly, CUR can enhance the uptake of DOX by Lewis lung carcinoma (LL/2) cells. The experimental results in vivo and in vitro showed that CUR-DOX/cRGD-M combination therapy could promote apoptosis of lung cancer cells, and conspicuously inhibit the tumor growth. Our data indicate that CUR-DOX/cRGD-M will be biodegradable and sustainable, which may have potential clinical application value in the treatment of lung cancer.
2022, 33(5): 2512-2516
doi: 10.1016/j.cclet.2021.12.087
Abstract:
Highly efficient removal of tumor necrosis factor-α (TNF-α) from plasma by hemoperfusion for autoimmune disease therapy remains a challenge in the clinical field owing to the low adsorption capacity and poor blood compatibility of adsorbents. In this work, a new class of nanobody (Nb)-coupled antifouling polyvinyl alcohol (PVA) beads was constructed as an immunosorbent for the selective removal of TNF-α from plasma. Notably, our immunosorbent exhibited an exceptionally high specific TNF-α adsorption capacity of 416.9 ng/g in human plasma (at a plasma-to-adsorbent ratio of 300). More importantly, the obtained adsorbent beads showed outstanding blood compatibility. In addition, during in vivo experiments, the blood circulation device was constructed to remove TNF-α in rat models, proving that the beads had good removal performance (~85%/60 min). Furthermore, 95% of the original capacity was retained after 6-month storage, showed strong stability and prolonged storage of PVA-Nb. Above all, the results indicate that the novel PVA-Nb immunosorbent has possible clinical applications for treating autoimmune diseases in the clinic.
Highly efficient removal of tumor necrosis factor-α (TNF-α) from plasma by hemoperfusion for autoimmune disease therapy remains a challenge in the clinical field owing to the low adsorption capacity and poor blood compatibility of adsorbents. In this work, a new class of nanobody (Nb)-coupled antifouling polyvinyl alcohol (PVA) beads was constructed as an immunosorbent for the selective removal of TNF-α from plasma. Notably, our immunosorbent exhibited an exceptionally high specific TNF-α adsorption capacity of 416.9 ng/g in human plasma (at a plasma-to-adsorbent ratio of 300). More importantly, the obtained adsorbent beads showed outstanding blood compatibility. In addition, during in vivo experiments, the blood circulation device was constructed to remove TNF-α in rat models, proving that the beads had good removal performance (~85%/60 min). Furthermore, 95% of the original capacity was retained after 6-month storage, showed strong stability and prolonged storage of PVA-Nb. Above all, the results indicate that the novel PVA-Nb immunosorbent has possible clinical applications for treating autoimmune diseases in the clinic.
2022, 33(5): 2541-2544
doi: 10.1016/j.cclet.2021.09.017
Abstract:
In this study, SB216763 and cyclosporine A were identified as anti-influenza A virus (IAV) agents by transcriptome signature reversion (TSR) analysis through deep mining of the cellular transcriptome of human airway and lung cell lines infected with 3 strains of IAV and the chemical perturbations library. A synergistic effect of SB216763 and cyclosporine A against influenza A was disclosed by quantification of the network-based relationship, which was validated in vitro. Along with burgeoning omics approaches, transcriptome-based drug development is flourishing, which provides a novel insight into antivirals discovery with comprehensive cellular transcriptional information of disease and chemical perturbations in multicomponent intervention. This strategy can be applied as a new approach in discovering multitarget antiviral agents from approved drugs, clinical compounds, natural products or other known bioactive compounds.
In this study, SB216763 and cyclosporine A were identified as anti-influenza A virus (IAV) agents by transcriptome signature reversion (TSR) analysis through deep mining of the cellular transcriptome of human airway and lung cell lines infected with 3 strains of IAV and the chemical perturbations library. A synergistic effect of SB216763 and cyclosporine A against influenza A was disclosed by quantification of the network-based relationship, which was validated in vitro. Along with burgeoning omics approaches, transcriptome-based drug development is flourishing, which provides a novel insight into antivirals discovery with comprehensive cellular transcriptional information of disease and chemical perturbations in multicomponent intervention. This strategy can be applied as a new approach in discovering multitarget antiviral agents from approved drugs, clinical compounds, natural products or other known bioactive compounds.
2022, 33(5): 2545-2549
doi: 10.1016/j.cclet.2021.09.059
Abstract:
Targeting RIPK1 is a promising strategy for the treatment or alleviation of acute lung injury (ALI). SZM594, a benzothiazole compound previously developed by our research group, possessed good dual-targeting receptor-interacting protein kinase 1 (RIPK1) and RIPK3 activity and anti-necroptosis activity as well as acceptable in vivo efficacy. In this study, the cyclopropyl moiety of SZM594 was modified based on a structure-based design strategy. The resulting cyclohexanone-containing analogue 41 improved the selectivity toward RIPK1 over RIPK3 and the anti-necroptosis activity was also increased compared with those of SZM594. More importantly, compound 41 could inhibit the tumor necrosis factor-α (TNF-α) expression in lipopolysaccharide (LPS)-induced peritoneal macrophage cell model, and significantly alleviate LPS-induced ALI in a mouse model. This compound could significantly inhibit the expressions of the phosphorylation of RIPK1 and down-stream RIPK3 and mixed lineage kinase domain-like protein (MLKL). Thus, these cyclohexanone-containing benzothiazole analogues represent promising lead structures for the discovery of novel protective agents of ALI.
Targeting RIPK1 is a promising strategy for the treatment or alleviation of acute lung injury (ALI). SZM594, a benzothiazole compound previously developed by our research group, possessed good dual-targeting receptor-interacting protein kinase 1 (RIPK1) and RIPK3 activity and anti-necroptosis activity as well as acceptable in vivo efficacy. In this study, the cyclopropyl moiety of SZM594 was modified based on a structure-based design strategy. The resulting cyclohexanone-containing analogue 41 improved the selectivity toward RIPK1 over RIPK3 and the anti-necroptosis activity was also increased compared with those of SZM594. More importantly, compound 41 could inhibit the tumor necrosis factor-α (TNF-α) expression in lipopolysaccharide (LPS)-induced peritoneal macrophage cell model, and significantly alleviate LPS-induced ALI in a mouse model. This compound could significantly inhibit the expressions of the phosphorylation of RIPK1 and down-stream RIPK3 and mixed lineage kinase domain-like protein (MLKL). Thus, these cyclohexanone-containing benzothiazole analogues represent promising lead structures for the discovery of novel protective agents of ALI.
2022, 33(5): 2550-2554
doi: 10.1016/j.cclet.2021.09.102
Abstract:
Plasmodium parasites causing malaria have developed resistance to most of the antimalarials in use, including the artemisinin-based combinations, which are the last line of defense against malaria. This necessitates the discovery of new targets and the development of novel antimalarials. Plasmodium falciparum alanyl aminopeptidase (PfA-M1) and leucyl aminopeptidase (PfA-M17) belong to the M1 and M17 family of metalloproteases respectively and play critical roles in the asexual erythrocytic stage of development. These enzymes have been suggested as potential antimalarial drug targets. Herein we describe the development of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors. Most of the compounds described in this study display inhibition at sub-micromolar range against the recombinant PfA-M1 and PfA-M17. More importantly, compound 26 not only exhibits potent malarial aminopeptidases inhibitory activities (PfA-M1 Ki = 0.11 ± 0.0002 µmol/L, PfA-M17 Ki = 0.05 ± 0.005 µmol/L), but also possesses remarkable selectivity over the mammalian counterpart (pAPN Ki = 17.24 ± 0.08 µmol/L), which endows 26 with strong inhibition of the malarial parasite growth and negligible cytotoxicity on human cell lines. Crystal structures of PfA-M1 at atomic resolution in complex with four different compounds including compound 26 establish the structural basis for their inhibitory activities. Notably, the terminal ureidobenzyl group of 26 explores the S2′ region where differences between the malarial and mammalian enzymes are apparent, which rationalizes the selectivity of 26. Together, our data provide important insights for the rational and structure-based design of selective and dual inhibitors of malarial aminopeptidases that will likely lead to novel chemotherapeutics for the treatment of malaria.
Plasmodium parasites causing malaria have developed resistance to most of the antimalarials in use, including the artemisinin-based combinations, which are the last line of defense against malaria. This necessitates the discovery of new targets and the development of novel antimalarials. Plasmodium falciparum alanyl aminopeptidase (PfA-M1) and leucyl aminopeptidase (PfA-M17) belong to the M1 and M17 family of metalloproteases respectively and play critical roles in the asexual erythrocytic stage of development. These enzymes have been suggested as potential antimalarial drug targets. Herein we describe the development of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors. Most of the compounds described in this study display inhibition at sub-micromolar range against the recombinant PfA-M1 and PfA-M17. More importantly, compound 26 not only exhibits potent malarial aminopeptidases inhibitory activities (PfA-M1 Ki = 0.11 ± 0.0002 µmol/L, PfA-M17 Ki = 0.05 ± 0.005 µmol/L), but also possesses remarkable selectivity over the mammalian counterpart (pAPN Ki = 17.24 ± 0.08 µmol/L), which endows 26 with strong inhibition of the malarial parasite growth and negligible cytotoxicity on human cell lines. Crystal structures of PfA-M1 at atomic resolution in complex with four different compounds including compound 26 establish the structural basis for their inhibitory activities. Notably, the terminal ureidobenzyl group of 26 explores the S2′ region where differences between the malarial and mammalian enzymes are apparent, which rationalizes the selectivity of 26. Together, our data provide important insights for the rational and structure-based design of selective and dual inhibitors of malarial aminopeptidases that will likely lead to novel chemotherapeutics for the treatment of malaria.
2022, 33(5): 2555-2558
doi: 10.1016/j.cclet.2021.09.064
Abstract:
Arnequinol A (1), featuring an unprecedented 6/6/3 tricyclic carbon skeleton fused with a heptatomic oxo-bridge, together with arnequinone A (2) bearing a highly conjugated methyl-shifting benzogeijerene skeleton, were isolated from Arnebia euchroma. Their structures were elucidated by extensive spectroscopic methods and quantum chemical calculations of the 13C nuclear magnetic resonance (NMR) data and electronic circular dichroism (ECD) spectra. The plausible biosynthetic pathways for 1 and 2 were presented. In in vitro test, compound 2 showed potent neuroprotective activity against serum-deprivation induced PC12 cell damage at a concentration of 10 µmol/L.
Arnequinol A (1), featuring an unprecedented 6/6/3 tricyclic carbon skeleton fused with a heptatomic oxo-bridge, together with arnequinone A (2) bearing a highly conjugated methyl-shifting benzogeijerene skeleton, were isolated from Arnebia euchroma. Their structures were elucidated by extensive spectroscopic methods and quantum chemical calculations of the 13C nuclear magnetic resonance (NMR) data and electronic circular dichroism (ECD) spectra. The plausible biosynthetic pathways for 1 and 2 were presented. In in vitro test, compound 2 showed potent neuroprotective activity against serum-deprivation induced PC12 cell damage at a concentration of 10 µmol/L.
2022, 33(5): 2559-2563
doi: 10.1016/j.cclet.2021.09.041
Abstract:
DNA-encoded chemical library (DEL) represents an emerging drug discovery technology to construct compound libraries with abundant chemical combinations. While drug-like small molecule DELs facilitate the discovery of binders against targets with defined pockets, macrocyclic DELs harboring extended scaffolds enable targeting of the protein–protein interaction (PPI) interface. We previously demonstrated the design of the first-generation DNA-encoded multiple display based on a constant macrocyclic scaffold, which harvested binders against difficult targets such as tumor necrosis factor-α (TNF-α). Here, we developed a novel strategy which utilized four orthogonal amine-protecting groups on DNA, to explore larger chemical combinations on the same constant macrocyclic scaffold, following the parallel paradigm to mimic the versatile antibody-like multivalent epitope recognition patterns. We successfully integrated these orthogonal protecting groups with acylation and made a mock second-generation DNA-encoded display combination. This work illustrates a strategy to produce larger encoded multiple display on a constant macrocyclic scaffold, which could facilitate potential binder discovery with enhanced affinity to clinically significant PPI targets.
DNA-encoded chemical library (DEL) represents an emerging drug discovery technology to construct compound libraries with abundant chemical combinations. While drug-like small molecule DELs facilitate the discovery of binders against targets with defined pockets, macrocyclic DELs harboring extended scaffolds enable targeting of the protein–protein interaction (PPI) interface. We previously demonstrated the design of the first-generation DNA-encoded multiple display based on a constant macrocyclic scaffold, which harvested binders against difficult targets such as tumor necrosis factor-α (TNF-α). Here, we developed a novel strategy which utilized four orthogonal amine-protecting groups on DNA, to explore larger chemical combinations on the same constant macrocyclic scaffold, following the parallel paradigm to mimic the versatile antibody-like multivalent epitope recognition patterns. We successfully integrated these orthogonal protecting groups with acylation and made a mock second-generation DNA-encoded display combination. This work illustrates a strategy to produce larger encoded multiple display on a constant macrocyclic scaffold, which could facilitate potential binder discovery with enhanced affinity to clinically significant PPI targets.
2022, 33(5): 2564-2568
doi: 10.1016/j.cclet.2021.09.050
Abstract:
Volatile organic compound (VOC) pollution has a serious impact on human and urgently needs to be controlled through the development of new methods and catalytic materials. Compared with traditional thermal catalytic oxidation, the synergistic photothermocatalysis is regarded as a green and environmentally friendly strategy for organic compound pollutant removal, which can promote spontaneous heating of the surface of catalysts to achieve thermal catalytic reaction conditions via harvesting light irradiation. In this paper, a monolithic photothermocatalyst was synthesized through coating graphene oxide (GO) and MnOx in turn on a commercially available melamine sponge, where the GO mainly acted as a photothermal conversion layer to heat the catalytically active MnOx. This monolithic catalyst presented excellent photo-induced activity for formaldehyde elimination under ambient conditions (~90% degradation ratio in 20 min for ~160 ppm initial concentration formaldehyde), and meanwhile possessed a high catalytic durability for multiple cycles. The kinetic study demonstrated that this photothermocatalytic process followed a pseudo-second-order kinetics. Finally, we proposed a possible formaldehyde degradation pathway based on in situ DRIFTS examination.
Volatile organic compound (VOC) pollution has a serious impact on human and urgently needs to be controlled through the development of new methods and catalytic materials. Compared with traditional thermal catalytic oxidation, the synergistic photothermocatalysis is regarded as a green and environmentally friendly strategy for organic compound pollutant removal, which can promote spontaneous heating of the surface of catalysts to achieve thermal catalytic reaction conditions via harvesting light irradiation. In this paper, a monolithic photothermocatalyst was synthesized through coating graphene oxide (GO) and MnOx in turn on a commercially available melamine sponge, where the GO mainly acted as a photothermal conversion layer to heat the catalytically active MnOx. This monolithic catalyst presented excellent photo-induced activity for formaldehyde elimination under ambient conditions (~90% degradation ratio in 20 min for ~160 ppm initial concentration formaldehyde), and meanwhile possessed a high catalytic durability for multiple cycles. The kinetic study demonstrated that this photothermocatalytic process followed a pseudo-second-order kinetics. Finally, we proposed a possible formaldehyde degradation pathway based on in situ DRIFTS examination.
2022, 33(5): 2569-2572
doi: 10.1016/j.cclet.2021.10.004
Abstract:
Improving the transfer hydrogenation of N-heteroarenes is of key importance for various industrial processes and remains a challenge so far. We reported here a microcapsule-pyrolysis strategy to quasi-continuous synthesis S, N co-doped carbon supported Co single atom catalysts (Co/SNC), which was used for transfer hydrogenation of quinoline with formic acid as the hydrogen donor. Given the unique geometric and electronic properties of the Co single atoms, the excellent catalytic activity, selectivity and stability were observed. Benefiting from the quasi-continuous synthesis method, the as-obtained catalysts provide a reference for the large-scale preparation of single atom catalysts without amplification effect. Highly catalytic performances and quasi-continuous preparation process, demonstrating a new and promising approach to rational design of atomically dispersed catalysts with maximum atomic efficiency in industrial.
Improving the transfer hydrogenation of N-heteroarenes is of key importance for various industrial processes and remains a challenge so far. We reported here a microcapsule-pyrolysis strategy to quasi-continuous synthesis S, N co-doped carbon supported Co single atom catalysts (Co/SNC), which was used for transfer hydrogenation of quinoline with formic acid as the hydrogen donor. Given the unique geometric and electronic properties of the Co single atoms, the excellent catalytic activity, selectivity and stability were observed. Benefiting from the quasi-continuous synthesis method, the as-obtained catalysts provide a reference for the large-scale preparation of single atom catalysts without amplification effect. Highly catalytic performances and quasi-continuous preparation process, demonstrating a new and promising approach to rational design of atomically dispersed catalysts with maximum atomic efficiency in industrial.
2022, 33(5): 2573-2578
doi: 10.1016/j.cclet.2021.08.078
Abstract:
Efficient conversion of straw cellulose to chemicals or fuels is an attracting topic today for the utilization of biomass to substitute for fossil resources. The development of catalysts is of vital importance. In this work, a composite catalyst metal-organic frameworks (MOFs) immobilized on three-dimensional reduced graphene oxide (3D-rGO) were synthesized by in situ growth of the MIL-101(Cr) within the 3D-rGO matrix. The supporting of 3D-rGO guaranteed the dispersion and acid site density of MIL-101(Cr). The MIL-101(Cr)@3D-rGO nanocomposite possesses excellent catalytic activity, stability, recyclability and is an idea catalyst for the efficient degradation of straw cellulose into formic acid (FA), acetic acid (AA) and oxalic acid (OA). A maximum FA conversion rates of 95.36% was obtained by using MIL-101(Cr)@3D-rGO(1:1) as catalyst and hydrothermal reaction at mild conditions of 200 ℃ for 1h in alkaline aqueous medium. The MIL-101(Cr)@3D-rGO nanocomposite can be reused with high catalytic activity without any collapse of structure or leaching of chromium.
Efficient conversion of straw cellulose to chemicals or fuels is an attracting topic today for the utilization of biomass to substitute for fossil resources. The development of catalysts is of vital importance. In this work, a composite catalyst metal-organic frameworks (MOFs) immobilized on three-dimensional reduced graphene oxide (3D-rGO) were synthesized by in situ growth of the MIL-101(Cr) within the 3D-rGO matrix. The supporting of 3D-rGO guaranteed the dispersion and acid site density of MIL-101(Cr). The MIL-101(Cr)@3D-rGO nanocomposite possesses excellent catalytic activity, stability, recyclability and is an idea catalyst for the efficient degradation of straw cellulose into formic acid (FA), acetic acid (AA) and oxalic acid (OA). A maximum FA conversion rates of 95.36% was obtained by using MIL-101(Cr)@3D-rGO(1:1) as catalyst and hydrothermal reaction at mild conditions of 200 ℃ for 1h in alkaline aqueous medium. The MIL-101(Cr)@3D-rGO nanocomposite can be reused with high catalytic activity without any collapse of structure or leaching of chromium.
2022, 33(5): 2579-2584
doi: 10.1016/j.cclet.2021.08.118
Abstract:
Adjusting the electronic structure of graphitic carbon nitride (g-C3N4) photocatalyst through π-π conjugation is an effective method to achieve efficient photogenerated carrier separation. One key challenge of π-π conjugation control is to tune the degree of such conjugation without destroying the g-C3N4 structure. Herein we report a conceptual design that achieves a coplanar heterojunction by enhancing the π-π conjugation via the doping of crystalline g-C3N4 using a conjugated double bond ring molecule, 1,3,5-benzenetriol, during calcination process. The selection of the dopant enables the facile creation of a unique coplanar heterojunction which not only retains the pristine network structure of g-C3N4, but remarkably promotes separation and transfer of photogenerated carriers through the enhanced π-conjugated endogenous electric field. As a result, the new g-C3N4 photocatalyst efficiently photocatalytically produces hydrogen from water under visible light irradiation with a high H2 production rate up to 94.94 μmol/h, and a notable external quantum efficiency of 16.4% at 420 nm.
Adjusting the electronic structure of graphitic carbon nitride (g-C3N4) photocatalyst through π-π conjugation is an effective method to achieve efficient photogenerated carrier separation. One key challenge of π-π conjugation control is to tune the degree of such conjugation without destroying the g-C3N4 structure. Herein we report a conceptual design that achieves a coplanar heterojunction by enhancing the π-π conjugation via the doping of crystalline g-C3N4 using a conjugated double bond ring molecule, 1,3,5-benzenetriol, during calcination process. The selection of the dopant enables the facile creation of a unique coplanar heterojunction which not only retains the pristine network structure of g-C3N4, but remarkably promotes separation and transfer of photogenerated carriers through the enhanced π-conjugated endogenous electric field. As a result, the new g-C3N4 photocatalyst efficiently photocatalytically produces hydrogen from water under visible light irradiation with a high H2 production rate up to 94.94 μmol/h, and a notable external quantum efficiency of 16.4% at 420 nm.
2022, 33(5): 2585-2589
doi: 10.1016/j.cclet.2021.09.108
Abstract:
Single metal atoms immobilized on a carbon substrate are of great potential for enhancing the catalytic activities for oxygen reduction and methanol oxidation reactions (ORR/MOR) owing to the maximized atom utilization. Herein, single copper atoms (SCAs) are loaded on macro-porous nitrogen-doped carbon (Cu-NC) derived from zeolitic imidazolate framework-8 (ZIF-8), which are used as catalysts for ORR and Pt-supports for MOR. For ORR, the catalyst marked as Cu-NC-3 exhibits a higher peak potential of 0.87 V (vs. Reversible hydrogen electrode) than that of commercial Pt/C (0.83 V), mainly attributing to that the 3D macro-porous structure of Cu-NC-3 provides adequate space for uniform dispersion of SCAs as the main active species, and smooth diffusion pathways for fast transport of substances (O2, H2O), therefore reducing the overpotential and the intermediate (H2O2) generation to enhance ORR activity. For MOR, Pt-Cu-NC-3 has a higher mass activity of 1217.4 mA/mgPt than that of Pt/C (752.4 mA/mgPt), and its activity maintenance (decline of 27.6%) is also better than Pt/C (decline of 44.0%) after 5000 cyclic voltammetry (CV) cycles. The interactions between SCAs and Pt nanoparticles should facilitate the generation of OH- from water molecules, which can fast eliminate the adsorbed CO to recover the Pt active sites to improve MOR performance. This synthesis strategy affords a new inspiration to prepare single metal atoms loaded on ZIFs-derived macro-structure with diverse activities for ORR/MOR.
Single metal atoms immobilized on a carbon substrate are of great potential for enhancing the catalytic activities for oxygen reduction and methanol oxidation reactions (ORR/MOR) owing to the maximized atom utilization. Herein, single copper atoms (SCAs) are loaded on macro-porous nitrogen-doped carbon (Cu-NC) derived from zeolitic imidazolate framework-8 (ZIF-8), which are used as catalysts for ORR and Pt-supports for MOR. For ORR, the catalyst marked as Cu-NC-3 exhibits a higher peak potential of 0.87 V (vs. Reversible hydrogen electrode) than that of commercial Pt/C (0.83 V), mainly attributing to that the 3D macro-porous structure of Cu-NC-3 provides adequate space for uniform dispersion of SCAs as the main active species, and smooth diffusion pathways for fast transport of substances (O2, H2O), therefore reducing the overpotential and the intermediate (H2O2) generation to enhance ORR activity. For MOR, Pt-Cu-NC-3 has a higher mass activity of 1217.4 mA/mgPt than that of Pt/C (752.4 mA/mgPt), and its activity maintenance (decline of 27.6%) is also better than Pt/C (decline of 44.0%) after 5000 cyclic voltammetry (CV) cycles. The interactions between SCAs and Pt nanoparticles should facilitate the generation of OH- from water molecules, which can fast eliminate the adsorbed CO to recover the Pt active sites to improve MOR performance. This synthesis strategy affords a new inspiration to prepare single metal atoms loaded on ZIFs-derived macro-structure with diverse activities for ORR/MOR.
2022, 33(5): 2590-2594
doi: 10.1016/j.cclet.2021.08.129
Abstract:
Reverse water gas shift (RWGS) reaction is a crucial process in CO2 utilization. Herein, Ni- and NiCe-containing hexagonal mesoporous silica (Ni-HMS and NiCe-HMS) catalysts were synthesized using an in-situ one-pot method and applied for RWGS reaction. At certain reaction temperatures 500-750 ℃, Ni-HMS samples displayed a higher selectivity to the preferable CO than that of conventionally impregnated Ni/HMS catalyst. This could be originated from the smaller NiO nanoparticles over Ni-HMS catalyst. NiCe-HMS exhibited higher activity compared to Ni-HMS. The catalysts were characterized by means of TEM, XPS, XRD, H2-TPR, CO2-TPD, EPR and N2 adsorption-desortion technology. It was found that introduction of Ce created high concentration of oxygen vacancies, served as the active site for activating CO2. Also, this work analyzed the effect of the H2/CO2 molar ratio on the best NiCe-HMS. When reaction gas H2/CO2 molar ratio was 4 significantly decreased the selectivity to CO at low temperature, but triggered a higher CO2 conversion which is close to the equilibrium.
Reverse water gas shift (RWGS) reaction is a crucial process in CO2 utilization. Herein, Ni- and NiCe-containing hexagonal mesoporous silica (Ni-HMS and NiCe-HMS) catalysts were synthesized using an in-situ one-pot method and applied for RWGS reaction. At certain reaction temperatures 500-750 ℃, Ni-HMS samples displayed a higher selectivity to the preferable CO than that of conventionally impregnated Ni/HMS catalyst. This could be originated from the smaller NiO nanoparticles over Ni-HMS catalyst. NiCe-HMS exhibited higher activity compared to Ni-HMS. The catalysts were characterized by means of TEM, XPS, XRD, H2-TPR, CO2-TPD, EPR and N2 adsorption-desortion technology. It was found that introduction of Ce created high concentration of oxygen vacancies, served as the active site for activating CO2. Also, this work analyzed the effect of the H2/CO2 molar ratio on the best NiCe-HMS. When reaction gas H2/CO2 molar ratio was 4 significantly decreased the selectivity to CO at low temperature, but triggered a higher CO2 conversion which is close to the equilibrium.
2022, 33(5): 2595-2599
doi: 10.1016/j.cclet.2021.12.041
Abstract:
We predicted two stable two-dimensional materials of carbon and bismuth elements, namely BiC and Bi2C monolayers. The stabilities of two monolayers were examined by cohesive energy, Born criteria, first-principle MD simulations and phonon spectra, respectively. By including the spin-orbit coupling effects, the BiC monolayer is a metal and the Bi2C monolayer possesses a narrow direct (indirect) band gap of 0.403 (0.126) eV under the HSE06 (GGA-PBE) functional. For the adsorption of CO2 molecules, the BiC and Bi2C monolayers have three stable adsorption sites C2, T3 and T4 with the adsorption energies as -0.57, -0.51 and -0.81 eV, and the activation ability on the adsorption as T4 > T3 > C2. These consequences make the BiC and Bi2C monolayers to be promising adsorbents to capture CO2 gas, the Bi2C monolayer to be well photovoltaics and optoelectronics material, and the BiC monolayer to be ideal battery and electronics materials, respectively.
We predicted two stable two-dimensional materials of carbon and bismuth elements, namely BiC and Bi2C monolayers. The stabilities of two monolayers were examined by cohesive energy, Born criteria, first-principle MD simulations and phonon spectra, respectively. By including the spin-orbit coupling effects, the BiC monolayer is a metal and the Bi2C monolayer possesses a narrow direct (indirect) band gap of 0.403 (0.126) eV under the HSE06 (GGA-PBE) functional. For the adsorption of CO2 molecules, the BiC and Bi2C monolayers have three stable adsorption sites C2, T3 and T4 with the adsorption energies as -0.57, -0.51 and -0.81 eV, and the activation ability on the adsorption as T4 > T3 > C2. These consequences make the BiC and Bi2C monolayers to be promising adsorbents to capture CO2 gas, the Bi2C monolayer to be well photovoltaics and optoelectronics material, and the BiC monolayer to be ideal battery and electronics materials, respectively.
2022, 33(5): 2600-2604
doi: 10.1016/j.cclet.2021.09.098
Abstract:
As a two-dimensional carbon based semiconductor, C3N acts as a promising material in many application areas. However, the basic physical properties such as Raman spectrum properties of C3N is still not clear. In this paper, we clarify the Raman spectrum properties of multilayer C3N. Moreover, the stacking driven Raman spectra change of multilayer C3N is also discussed.
As a two-dimensional carbon based semiconductor, C3N acts as a promising material in many application areas. However, the basic physical properties such as Raman spectrum properties of C3N is still not clear. In this paper, we clarify the Raman spectrum properties of multilayer C3N. Moreover, the stacking driven Raman spectra change of multilayer C3N is also discussed.
2022, 33(5): 2605-2610
doi: 10.1016/j.cclet.2021.09.042
Abstract:
Three imidazole-modified Ag-polyoxovanadates frameworks (APFs) with a controllable molar ratio of Ag+ to polyoxovanadates (POVs) [Ag(IM)2]2V4O122Ag(IM)2 (APF-1), [Ag2(1-eIM)4]2[Ag(1-eIM)2]32Ag(1-eIM)23(1-HeIM)[V10O28]2 (APF-2) and [Ag(1-pIM)2]3[HV10O28]2Ag(1-pIM)22H2O (APF-3) (IM = imidazole; 1-eIM = 1-ethylimidazole and 1-pIM = 1-propylimidazole) have been successfully achieved by self-assembly of POVs, Ag+ cations, and three different imidazole derivatives. Interestingly, the molar ratios of Ag+ to POVs vary from 4:1, 4.5:1 to 5:1 by changing the vanadium resources and imidazole derivatives. Notably, the coordination environment of Ag+ cations and the structure of POVs in the APFs are also different. Specifically, for APF-1, the four Ag atoms adopt three-coordinated and four-coordinated geometries, respectively, and Ag-imidazole complexes and [V4O12]4− cluster form the one-dimensional polymeric chains. While Ag atoms in APF-2 and APF-3 exhibit two-, four- and five-coordinated geometries for APF-2, four-, five- and six-coordinated geometries for APF-3, respectively. These Ag+ cations and decavanadate clusters are assembled into the 2D supramolecular structure through the Ag-O bonds and Ag…Ag argentophilic interaction. Remarkably, thus-obtained APF-2 can serve as powerful efficient heterogeneous catalyst for construction of CN bond and detoxification of simulant sulfur mustard (yields up to 99%), which enable successful recycling for three cycles with remained catalytic activities and structure stability.
Three imidazole-modified Ag-polyoxovanadates frameworks (APFs) with a controllable molar ratio of Ag+ to polyoxovanadates (POVs) [Ag(IM)2]2V4O122Ag(IM)2 (APF-1), [Ag2(1-eIM)4]2[Ag(1-eIM)2]32Ag(1-eIM)23(1-HeIM)[V10O28]2 (APF-2) and [Ag(1-pIM)2]3[HV10O28]2Ag(1-pIM)22H2O (APF-3) (IM = imidazole; 1-eIM = 1-ethylimidazole and 1-pIM = 1-propylimidazole) have been successfully achieved by self-assembly of POVs, Ag+ cations, and three different imidazole derivatives. Interestingly, the molar ratios of Ag+ to POVs vary from 4:1, 4.5:1 to 5:1 by changing the vanadium resources and imidazole derivatives. Notably, the coordination environment of Ag+ cations and the structure of POVs in the APFs are also different. Specifically, for APF-1, the four Ag atoms adopt three-coordinated and four-coordinated geometries, respectively, and Ag-imidazole complexes and [V4O12]4− cluster form the one-dimensional polymeric chains. While Ag atoms in APF-2 and APF-3 exhibit two-, four- and five-coordinated geometries for APF-2, four-, five- and six-coordinated geometries for APF-3, respectively. These Ag+ cations and decavanadate clusters are assembled into the 2D supramolecular structure through the Ag-O bonds and Ag…Ag argentophilic interaction. Remarkably, thus-obtained APF-2 can serve as powerful efficient heterogeneous catalyst for construction of CN bond and detoxification of simulant sulfur mustard (yields up to 99%), which enable successful recycling for three cycles with remained catalytic activities and structure stability.
2022, 33(5): 2611-2616
doi: 10.1016/j.cclet.2021.09.094
Abstract:
The properties of two-dimensional (2D) materials are highly dependent on their phase and thickness. Various phases exist in tin disulfide (SnS2), resulting in promising electronic and optical properties. Hence, accurately identifying the phase and thickness of SnS2 nanosheets is prior to their optoelectronic applications. Herein, layered 2H-SnS2 and 4H-SnS2 crystals were grown by chemical vapor transportation and the crystalline phase of SnS2 was characterized by X-ray diffraction, ultralow frequency (ULF) Raman spectroscopy and high-resolution transmission electron microscope. As-grown crystals were mechanically exfoliated to single- and few-layer nanosheets, which were investigated by optical microscopy, atomic force microscopy and ULF Raman spectroscopy. Although the 2H-SnS2 and 4H-SnS2 nanosheets have similar optical contrast on SiO2/Si substrates, their ULF Raman spectra obviously show different shear and breathing modes, which are highly dependent on their phases and thicknesses. Interestingly, the SnS2 nanosheets have shown phase-dependent electrical properties. The 4H-SnS2 nanosheet shows a current on/off ratio of 2.58 × 105 and excellent photosensitivity, which are much higher than those of the 2H-SnS2 nanosheet. Our work not only offers an accurate method for identifying single- and few-layer SnS2 nanosheets with different phases, but also paves the way for the application of SnS2 nanosheets in high-performance optoelectronic devices.
The properties of two-dimensional (2D) materials are highly dependent on their phase and thickness. Various phases exist in tin disulfide (SnS2), resulting in promising electronic and optical properties. Hence, accurately identifying the phase and thickness of SnS2 nanosheets is prior to their optoelectronic applications. Herein, layered 2H-SnS2 and 4H-SnS2 crystals were grown by chemical vapor transportation and the crystalline phase of SnS2 was characterized by X-ray diffraction, ultralow frequency (ULF) Raman spectroscopy and high-resolution transmission electron microscope. As-grown crystals were mechanically exfoliated to single- and few-layer nanosheets, which were investigated by optical microscopy, atomic force microscopy and ULF Raman spectroscopy. Although the 2H-SnS2 and 4H-SnS2 nanosheets have similar optical contrast on SiO2/Si substrates, their ULF Raman spectra obviously show different shear and breathing modes, which are highly dependent on their phases and thicknesses. Interestingly, the SnS2 nanosheets have shown phase-dependent electrical properties. The 4H-SnS2 nanosheet shows a current on/off ratio of 2.58 × 105 and excellent photosensitivity, which are much higher than those of the 2H-SnS2 nanosheet. Our work not only offers an accurate method for identifying single- and few-layer SnS2 nanosheets with different phases, but also paves the way for the application of SnS2 nanosheets in high-performance optoelectronic devices.
2022, 33(5): 2617-2620
doi: 10.1016/j.cclet.2021.09.079
Abstract:
Molybdenum trioxide (MoO3) can be employed as an excellent host for intercalation due to its 2D layered structure that connected by van der Waals interactions. Herein, a series of polyoxometalate-based MoO3 composites (Al13@MoO3) were successfully prepared by interpolating the Keggin-type polycationic AlO4Al12(OH)24(H2O)127+ (Al13) into MoO3 gallery. These composites can be applied to rapidly adsorb the anionic dye methyl orange (MO) through strong electrostatic interactions lead to compact and stable gathering in the surrounding of the numerous charged Al13. Adsorption behaviors of composites with the different amount of Al13 were determined, these results revealed that Al13-3.34%@MoO3 exhibited the most remarkable adsorption capacity. More importantly, the composite maintains superior adsorption capacity for five consecutive adsorption/desorption cycles, suggesting that Al13@MoO3 can be an efficient and durable adsorbent.
Molybdenum trioxide (MoO3) can be employed as an excellent host for intercalation due to its 2D layered structure that connected by van der Waals interactions. Herein, a series of polyoxometalate-based MoO3 composites (Al13@MoO3) were successfully prepared by interpolating the Keggin-type polycationic AlO4Al12(OH)24(H2O)127+ (Al13) into MoO3 gallery. These composites can be applied to rapidly adsorb the anionic dye methyl orange (MO) through strong electrostatic interactions lead to compact and stable gathering in the surrounding of the numerous charged Al13. Adsorption behaviors of composites with the different amount of Al13 were determined, these results revealed that Al13-3.34%@MoO3 exhibited the most remarkable adsorption capacity. More importantly, the composite maintains superior adsorption capacity for five consecutive adsorption/desorption cycles, suggesting that Al13@MoO3 can be an efficient and durable adsorbent.
2022, 33(5): 2621-2624
doi: 10.1016/j.cclet.2021.09.082
Abstract:
Though Olefin-linked covalent organic frameworks (oCOFs) possess excellent π-electron delocalization, the barely reversible olefin linkage brings challenges for oCOFs' synthesis and functionalization. Here, we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature. Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the possibility of aggregation-caused quenching. Photoelectrical measurements and electric band structure calculation both verify the superiority of this oCOFs' structure in photoelectric sensing.
Though Olefin-linked covalent organic frameworks (oCOFs) possess excellent π-electron delocalization, the barely reversible olefin linkage brings challenges for oCOFs' synthesis and functionalization. Here, we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature. Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the possibility of aggregation-caused quenching. Photoelectrical measurements and electric band structure calculation both verify the superiority of this oCOFs' structure in photoelectric sensing.
2022, 33(5): 2625-2629
doi: 10.1016/j.cclet.2021.09.093
Abstract:
By combining 5, 10, 15, 20-tetra(4-chlorine)phenylporphyrin (TClPP) and α-Keggin polyoxometalate H5PV2Mo10O40 (H5PVMo) via a simple ion-exchange method, an organic-inorganic hybrid material [C44H28N4Cl4]1.5[H2PMo10V2O40]·2C2H6O (H2TClPP-H2PVMo) was prepared and thoroughly characterized by a variety of techniques. The homogeneous photocatalytic degradation of 2-chloroethyl ethyl sulfide (CEES) (5 µL) by H2TClPP-H2PVMo (1 × 10−6 mol/L) was studied in methanol and methanol-water mixed solvent (v/v = 1:1), in which the degradation rate of CEES reached 99.52% and 99.14%, respectively. The reaction followed first-order reaction kinetics, and the half-life and kinetic constant in methanol and the mixed solvent were respectively 33.0 min, −0.021 min−1 and 15.7 min, −0.043 min−1. Mechanism analysis indicated that under visible light irradiation in the air, CEES was degraded via oxidation and alcoholysis/hydrolysis in methanol and the mixed solvent. O2·− and 1O2 generated by H2TClPP-H2PVMo selectively oxidized CEES into a nontoxic sulfoxide. Singlet oxygen capture experiments showed that H2TClPP-H2PVMo (ϕ = 0.73) had a higher quantum yield of singlet oxygen than TClPP (ϕ = 0.35) under an air atmosphere and visible light irradiation.
By combining 5, 10, 15, 20-tetra(4-chlorine)phenylporphyrin (TClPP) and α-Keggin polyoxometalate H5PV2Mo10O40 (H5PVMo) via a simple ion-exchange method, an organic-inorganic hybrid material [C44H28N4Cl4]1.5[H2PMo10V2O40]·2C2H6O (H2TClPP-H2PVMo) was prepared and thoroughly characterized by a variety of techniques. The homogeneous photocatalytic degradation of 2-chloroethyl ethyl sulfide (CEES) (5 µL) by H2TClPP-H2PVMo (1 × 10−6 mol/L) was studied in methanol and methanol-water mixed solvent (v/v = 1:1), in which the degradation rate of CEES reached 99.52% and 99.14%, respectively. The reaction followed first-order reaction kinetics, and the half-life and kinetic constant in methanol and the mixed solvent were respectively 33.0 min, −0.021 min−1 and 15.7 min, −0.043 min−1. Mechanism analysis indicated that under visible light irradiation in the air, CEES was degraded via oxidation and alcoholysis/hydrolysis in methanol and the mixed solvent. O2·− and 1O2 generated by H2TClPP-H2PVMo selectively oxidized CEES into a nontoxic sulfoxide. Singlet oxygen capture experiments showed that H2TClPP-H2PVMo (ϕ = 0.73) had a higher quantum yield of singlet oxygen than TClPP (ϕ = 0.35) under an air atmosphere and visible light irradiation.
2022, 33(5): 2630-2634
doi: 10.1016/j.cclet.2021.09.078
Abstract:
An organic-inorganic hybrid FeIII–PrIII-included 2-germano-20-tungstate [Pr(H2O)8]2H2[Fe4(H2O)4 (pca)4Ge2W20O72]•34H2O (Hpca = 2-pyridinecarboxylic acid) (1) was hydrothermally prepared. Its polyoxoanion comprises one tetra-FeIII incorporated [Fe4(H2O)4(pca)4Ge2W20O72]8- hybrid entity and two [Pr(H2O)8]3+ ornamental cations. The [Fe4(H2O)4(pca)4Ge2W20O72]8- 2-germano-20-tungstate entity can be regarded as an infrequent S-type [Ge2W20O72]16- cluster pocketed by four [Fe(H2O)(pca)]2+ cations. The S-type [Ge2W20O72]16- cluster could be imagined as condensation of two divacant Keggin [α-GeW10O37]10- segments by sharing two atoms. It is of interest is that carboxyl O and pyridine N atoms on pca ligands concurrently bind with Fe3+ cations in a five-membered heterocyclic fashion to increase the stability of the whole structure. Furthermore, the electrochemical biosensing properties of 1 as the modified electrode material have been investigated for detecting norepinephrine (NPP), showing a low detection limit of 3.25 µmol/L. This work not only enriches structures of heterometallic germanotungstates (GTs), but also expands applications of polyoxometalates (POMs) in the electrochemical biosensing field.
An organic-inorganic hybrid FeIII–PrIII-included 2-germano-20-tungstate [Pr(H2O)8]2H2[Fe4(H2O)4 (pca)4Ge2W20O72]•34H2O (Hpca = 2-pyridinecarboxylic acid) (1) was hydrothermally prepared. Its polyoxoanion comprises one tetra-FeIII incorporated [Fe4(H2O)4(pca)4Ge2W20O72]8- hybrid entity and two [Pr(H2O)8]3+ ornamental cations. The [Fe4(H2O)4(pca)4Ge2W20O72]8- 2-germano-20-tungstate entity can be regarded as an infrequent S-type [Ge2W20O72]16- cluster pocketed by four [Fe(H2O)(pca)]2+ cations. The S-type [Ge2W20O72]16- cluster could be imagined as condensation of two divacant Keggin [α-GeW10O37]10- segments by sharing two atoms. It is of interest is that carboxyl O and pyridine N atoms on pca ligands concurrently bind with Fe3+ cations in a five-membered heterocyclic fashion to increase the stability of the whole structure. Furthermore, the electrochemical biosensing properties of 1 as the modified electrode material have been investigated for detecting norepinephrine (NPP), showing a low detection limit of 3.25 µmol/L. This work not only enriches structures of heterometallic germanotungstates (GTs), but also expands applications of polyoxometalates (POMs) in the electrochemical biosensing field.
2022, 33(5): 2635-2638
doi: 10.1016/j.cclet.2021.09.075
Abstract:
Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility. However, the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications. Herein, we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations, through a simple in-situ polymerization. In this composite hydrogel actuator, the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to provide bending and even other complex deformations. Owing to strong interfacial interaction, this actuator perfectly realized the combination of good mechanical properties (~1.1 MPa) and fast actuation speed (~0.9 s). In addition, by adjusting the orientation direction of wood, this actuator can achieve various complex deformations. Such composite hydrogel actuator could be a good candidate for intelligent applications, such as intelligent actuators, smart valves, manipulators and even soft robots.
Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility. However, the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications. Herein, we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations, through a simple in-situ polymerization. In this composite hydrogel actuator, the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to provide bending and even other complex deformations. Owing to strong interfacial interaction, this actuator perfectly realized the combination of good mechanical properties (~1.1 MPa) and fast actuation speed (~0.9 s). In addition, by adjusting the orientation direction of wood, this actuator can achieve various complex deformations. Such composite hydrogel actuator could be a good candidate for intelligent applications, such as intelligent actuators, smart valves, manipulators and even soft robots.
2022, 33(5): 2639-2642
doi: 10.1016/j.cclet.2021.09.054
Abstract:
The development of efficient method to prepare poly(silyl ether)s (PSEs) is highly desirable. Herein, an environmentally sustainable copper-catalyzed dehydrocoupling polymerization was developed with good yields and high molecular weight (up to 48, 400 of Mn and up to 97% yield). Monomers of different types (AB type or AA and BB type) are suitable to afford PSEs. The PSEs show good thermal stability and low glass-transition temperature.
The development of efficient method to prepare poly(silyl ether)s (PSEs) is highly desirable. Herein, an environmentally sustainable copper-catalyzed dehydrocoupling polymerization was developed with good yields and high molecular weight (up to 48, 400 of Mn and up to 97% yield). Monomers of different types (AB type or AA and BB type) are suitable to afford PSEs. The PSEs show good thermal stability and low glass-transition temperature.
2022, 33(5): 2643-2647
doi: 10.1016/j.cclet.2021.09.031
Abstract:
Cationic polymers, also known as polycations, are considered to be the most potential non-viral gene carriers due to their unique advantages such as the ability to bind the negative charge of nucleic acid molecules. Multicomponent polymerization (MCP) is a one-step, tandem strategy to construct complex structures based on multicomponent reactions. Herein, we developed a metal-free MCP method based on three monomers of p-dinitrovinylbenzene (p-DNVB), 1, 1-dimethylethyl N, N-dibromocarbamate (BocNBr2), and bis-secondary-amines with a ratio of 1:2:1, to access a library of Boc-substituted polyamidines with well-defined structures and suitable molecular weights (Mw ranging from 4400 Da to 11, 000 Da) in high yields (up to 85%) under mild conditions. Upon the removal of Boc groups, a series of water-soluble polymers with cationic property were prepared and their gene binding capability was further evaluated.
Cationic polymers, also known as polycations, are considered to be the most potential non-viral gene carriers due to their unique advantages such as the ability to bind the negative charge of nucleic acid molecules. Multicomponent polymerization (MCP) is a one-step, tandem strategy to construct complex structures based on multicomponent reactions. Herein, we developed a metal-free MCP method based on three monomers of p-dinitrovinylbenzene (p-DNVB), 1, 1-dimethylethyl N, N-dibromocarbamate (BocNBr2), and bis-secondary-amines with a ratio of 1:2:1, to access a library of Boc-substituted polyamidines with well-defined structures and suitable molecular weights (Mw ranging from 4400 Da to 11, 000 Da) in high yields (up to 85%) under mild conditions. Upon the removal of Boc groups, a series of water-soluble polymers with cationic property were prepared and their gene binding capability was further evaluated.
2022, 33(5): 2648-2652
doi: 10.1016/j.cclet.2021.09.040
Abstract:
Aqueous rechargeable Ni−Zn batteries are considered as a new generation of safe and reliable electrochemical energy storage system. However, low electronic conductivity of Ni-based cathodes hinders the practical application of Ni-Zn batteries. This problem can be overcome by compositing the Ni-based cathode with highly conductive carbon substrates. A chemical oxidation pre-treatment is popularly applied to the carbon substrates to increase their hydrophilicity and thus facilitate the growth of active materials in aqueous systems. However, the anodic stability of the oxidized carbon substrates is greatly challenged, which has never been addressed in previous reports. In this work, we first compared the anodic stability of carbon fiber paper with and without oxidation treatment and find that carbon substrate with the chemical treatment caused remarkable oxidization current in the required voltage range. To take both anodic stability and fine growth of active materials into account, here we demonstrated a facile physical surface-treatment method of ethanol wetting to replace the chemical treatment. The ethanol infiltration removes gas adsorption on carbon substrates and thus promotes their hydrophilicity. This cost-effective strategy simultaneously achieves a high anodic stability and a fine growth and uniform distribution of nickel-cobalt hydroxide on the carbon microfibers. The resulting Ni-Zn battery provides a high discharge capacity of 219 mAh/g with an operation cell voltage of 1.75 V.
Aqueous rechargeable Ni−Zn batteries are considered as a new generation of safe and reliable electrochemical energy storage system. However, low electronic conductivity of Ni-based cathodes hinders the practical application of Ni-Zn batteries. This problem can be overcome by compositing the Ni-based cathode with highly conductive carbon substrates. A chemical oxidation pre-treatment is popularly applied to the carbon substrates to increase their hydrophilicity and thus facilitate the growth of active materials in aqueous systems. However, the anodic stability of the oxidized carbon substrates is greatly challenged, which has never been addressed in previous reports. In this work, we first compared the anodic stability of carbon fiber paper with and without oxidation treatment and find that carbon substrate with the chemical treatment caused remarkable oxidization current in the required voltage range. To take both anodic stability and fine growth of active materials into account, here we demonstrated a facile physical surface-treatment method of ethanol wetting to replace the chemical treatment. The ethanol infiltration removes gas adsorption on carbon substrates and thus promotes their hydrophilicity. This cost-effective strategy simultaneously achieves a high anodic stability and a fine growth and uniform distribution of nickel-cobalt hydroxide on the carbon microfibers. The resulting Ni-Zn battery provides a high discharge capacity of 219 mAh/g with an operation cell voltage of 1.75 V.
2022, 33(5): 2653-2657
doi: 10.1016/j.cclet.2021.09.083
Abstract:
Aqueous zinc anodes have attracted the attention of many researchers owing to their high safety, low cost, and high theoretical specific capacity. However, its practical application is severely limited by the dendrite growth on zinc anode. Herein, we develop an intrinsically zincophobic barium-titanate protective layer with a porous structure to suppress the zinc dendrite formation by homogenizing the ion distribution on the anode surface, increasing the nucleation sites, and limiting the irregular zinc growth. Based on these synergistic effects, the coated zinc anode can exhibit long cycle life (840 h at 0.5 mA/cm2 for 0.5 mAh/cm2) and low voltage hysteresis (36 mV). This work can provide a feasible direction for the design of intrinsically zincophobic coating materials to uniformize the zinc stripping and plating.
Aqueous zinc anodes have attracted the attention of many researchers owing to their high safety, low cost, and high theoretical specific capacity. However, its practical application is severely limited by the dendrite growth on zinc anode. Herein, we develop an intrinsically zincophobic barium-titanate protective layer with a porous structure to suppress the zinc dendrite formation by homogenizing the ion distribution on the anode surface, increasing the nucleation sites, and limiting the irregular zinc growth. Based on these synergistic effects, the coated zinc anode can exhibit long cycle life (840 h at 0.5 mA/cm2 for 0.5 mAh/cm2) and low voltage hysteresis (36 mV). This work can provide a feasible direction for the design of intrinsically zincophobic coating materials to uniformize the zinc stripping and plating.
2022, 33(5): 2658-2662
doi: 10.1016/j.cclet.2021.09.100
Abstract:
Applying mixed oxygen ionic and electronic conducting (MIEC) oxides as the cathode offers a promising solution to enhance the performance of solid oxide fuel cells (SOFCs). However, the phase instability in CO2-containing air and sluggish oxygen reduction activity of MIEC cathodes remain a long-term challenge for optimizing the electrochemical performance of SOFCs. Herein, a heterovalent co-doping strategy is proposed to enhance the oxygen reduction activity and CO2 tolerance of SOFCs cathodes, which can be demonstrated by developing a novel BaCo0.6Fe0.4O3-δ (BCF)-based MIEC oxide, BaCo0.6Fe0.2Sn0.1Y0.1O3-δ (BCFSY). In addition to improving the stability of BCF-based perovskites, this strategy achieves an optimized balance of ionic mobility and oxygen vacancies due to the synergies between the effects of the co-dopants. Compared with single-doped materials, BCFSY exhibits improved CO2 tolerance and considerably higher ORR activity, which is reflected in a significantly lower polarization resistance of 0.15 Ω cm2 at 600 ℃. The results of this work provide an efficient tactic for designing electrode materials for SOFCs.
Applying mixed oxygen ionic and electronic conducting (MIEC) oxides as the cathode offers a promising solution to enhance the performance of solid oxide fuel cells (SOFCs). However, the phase instability in CO2-containing air and sluggish oxygen reduction activity of MIEC cathodes remain a long-term challenge for optimizing the electrochemical performance of SOFCs. Herein, a heterovalent co-doping strategy is proposed to enhance the oxygen reduction activity and CO2 tolerance of SOFCs cathodes, which can be demonstrated by developing a novel BaCo0.6Fe0.4O3-δ (BCF)-based MIEC oxide, BaCo0.6Fe0.2Sn0.1Y0.1O3-δ (BCFSY). In addition to improving the stability of BCF-based perovskites, this strategy achieves an optimized balance of ionic mobility and oxygen vacancies due to the synergies between the effects of the co-dopants. Compared with single-doped materials, BCFSY exhibits improved CO2 tolerance and considerably higher ORR activity, which is reflected in a significantly lower polarization resistance of 0.15 Ω cm2 at 600 ℃. The results of this work provide an efficient tactic for designing electrode materials for SOFCs.
2022, 33(5): 2663-2668
doi: 10.1016/j.cclet.2021.09.091
Abstract:
Zinc-ion batteries (ZIBs), in particular quasi-solid-state ZIBs, occupy a crucial position in the field of energy storage devices owing to the superiorities of abundant zinc reserve, low cost, high safety and high theoretical capacity of zinc anode. However, as divalent Zn2+ ions experience strong electrostatic interactions when intercalating into the cathode materials, which poses challenges to the structural stability and higher demand in Zn2+ ions diffusion kinetics of the cathode materials. Here, a microwave-assisted hydrothermal method is adopted to prepare pre-potassiated hydrated vanadium pentoxide (K0.52V2O5·0.29H2O, abbreviated as KHVO) cathode material, in which the potassium ions pre-inserted into the interlayers can act as "pillars" to stabilize the lamellar structure, and crystal water can act as "lubricant" to improve the diffusion efficiency of Zn2+ ions. Consequently, the KHVO displays high electrochemical properties with high capacity (~300 mAh/g), superior rate capability (69 mAh/g at 5 A/g) and ultralong cycling performance (> 1500 cycles at 2 A/g) in quasi-solid-state ZIBs. These superior Zn storage properties result from the large diffusion coefficient and highly stable and reversible Zn2+ (de)intercalation reaction of KHVO.
Zinc-ion batteries (ZIBs), in particular quasi-solid-state ZIBs, occupy a crucial position in the field of energy storage devices owing to the superiorities of abundant zinc reserve, low cost, high safety and high theoretical capacity of zinc anode. However, as divalent Zn2+ ions experience strong electrostatic interactions when intercalating into the cathode materials, which poses challenges to the structural stability and higher demand in Zn2+ ions diffusion kinetics of the cathode materials. Here, a microwave-assisted hydrothermal method is adopted to prepare pre-potassiated hydrated vanadium pentoxide (K0.52V2O5·0.29H2O, abbreviated as KHVO) cathode material, in which the potassium ions pre-inserted into the interlayers can act as "pillars" to stabilize the lamellar structure, and crystal water can act as "lubricant" to improve the diffusion efficiency of Zn2+ ions. Consequently, the KHVO displays high electrochemical properties with high capacity (~300 mAh/g), superior rate capability (69 mAh/g at 5 A/g) and ultralong cycling performance (> 1500 cycles at 2 A/g) in quasi-solid-state ZIBs. These superior Zn storage properties result from the large diffusion coefficient and highly stable and reversible Zn2+ (de)intercalation reaction of KHVO.
2022, 33(5): 2669-2676
doi: 10.1016/j.cclet.2021.09.103
Abstract:
Developing transition metal oxides (TMOs) with high energy, power, and long cycle lifetime for electric energy storage devices remains a critical challenge to date. Herein, we demonstrate a facile method that enables in-situ transformation of nickel cobalt oxide nanowire arrays (NiCoO NWA) into hierarchical nanowire-nanosheet arrays (ac-NiCoO NWSA) for enhanced energy storage properties. More specifically, the method leads to formation of atomically thin nanosheets (only 2.0 nm) and creates abundant antisite defects and oxygen vacancies. Owing to these merits, the as-prepared ac-NiCoO NWSA electrode exhibits over five-fold higher specific capacity, superior rate capability (up to 100 A/g), and excellent cycling stability of 10, 000 cycles at 50 A/g in alkaline electrolyte compared to pristine NiCoO NWA. Density functional theory (DFT) simulations elucidate the electrochemical activity enhancement mechanism of the TMOs. Moreover, our method triggers similar structural reconstruction phenomenon on other TMOs including ZnCo-, CoMn- and ZnNiCo-oxides, proving the universality of the method. Our findings provide a general method towards simultaneously manipulating the micro-morphologies and defects of TMOs for advanced energy storage devices.
Developing transition metal oxides (TMOs) with high energy, power, and long cycle lifetime for electric energy storage devices remains a critical challenge to date. Herein, we demonstrate a facile method that enables in-situ transformation of nickel cobalt oxide nanowire arrays (NiCoO NWA) into hierarchical nanowire-nanosheet arrays (ac-NiCoO NWSA) for enhanced energy storage properties. More specifically, the method leads to formation of atomically thin nanosheets (only 2.0 nm) and creates abundant antisite defects and oxygen vacancies. Owing to these merits, the as-prepared ac-NiCoO NWSA electrode exhibits over five-fold higher specific capacity, superior rate capability (up to 100 A/g), and excellent cycling stability of 10, 000 cycles at 50 A/g in alkaline electrolyte compared to pristine NiCoO NWA. Density functional theory (DFT) simulations elucidate the electrochemical activity enhancement mechanism of the TMOs. Moreover, our method triggers similar structural reconstruction phenomenon on other TMOs including ZnCo-, CoMn- and ZnNiCo-oxides, proving the universality of the method. Our findings provide a general method towards simultaneously manipulating the micro-morphologies and defects of TMOs for advanced energy storage devices.
2022, 33(5): 2677-2680
doi: 10.1016/j.cclet.2021.09.021
Abstract:
The high effective nano-hybrid pour point depressant (PPD) has attracted extensive attention for its potential application in improving the cold flow properties of diesel fuel. In this paper, the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths (i.e., tetradecyl, hexadecyl, and octodecyl) of n-alkyl methacrylate-maleic anhydride copolymers (R1MC-MA, R1 = C14, C16, C18) and SiO2 nanoparticles. The effect of those nano-hybrid PPDs on the cold filter plugging point (CFPP) and solidifying point (SP) depressing of diesel fuel were studied. Results indicated that nano-hybrid PPD showed much better performance on diesel fuel. The diesel fuel treated with 0.2 wt% C14MC-MA/SiO2 nano-hybrid PPD exhibited the best depression in CFPP and SP by 6 ℃ and 18 ℃, respectively, which higher than that of single C14MC-MA. Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism; and results presented that nano-hybrid PPD of C14MC-MA/SiO2 could effectively lower the low-temperature viscosity, and modify the crystallization behavior and crystal morphology of diesel. Therefore, the cold flow properties of diesel were significantly improved.
The high effective nano-hybrid pour point depressant (PPD) has attracted extensive attention for its potential application in improving the cold flow properties of diesel fuel. In this paper, the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths (i.e., tetradecyl, hexadecyl, and octodecyl) of n-alkyl methacrylate-maleic anhydride copolymers (R1MC-MA, R1 = C14, C16, C18) and SiO2 nanoparticles. The effect of those nano-hybrid PPDs on the cold filter plugging point (CFPP) and solidifying point (SP) depressing of diesel fuel were studied. Results indicated that nano-hybrid PPD showed much better performance on diesel fuel. The diesel fuel treated with 0.2 wt% C14MC-MA/SiO2 nano-hybrid PPD exhibited the best depression in CFPP and SP by 6 ℃ and 18 ℃, respectively, which higher than that of single C14MC-MA. Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism; and results presented that nano-hybrid PPD of C14MC-MA/SiO2 could effectively lower the low-temperature viscosity, and modify the crystallization behavior and crystal morphology of diesel. Therefore, the cold flow properties of diesel were significantly improved.
2022, 33(5): 2681-2686
doi: 10.1016/j.cclet.2021.08.123
Abstract:
A facile fabrication strategy is reported to obtain N/O codoped porous carbon nanosheets for purpose of ameliorating the charge transfer and accumulation in the concentrated LiTFSI (lithium bis(trifluoromethane sulfonyl)imide) electrolyte. By tunning the feed ratio of comonomers, the porous nanosheet structure is endowed with a significant ion-adsorption surface area (1630 m2/g) and interconnected hierarchical porosity; meanwhile, high-level N/O dopants (N: 3.58 at%, O: 12.91 at%) increase the effective contact area for electrolyte ions, and further facilitate rapid ion/electron transfer. Benefiting from the advantageous features, carbon nanosheets electrode reveal an enhanced specific capacitance (375 F/g) in three-electrode configuration and the H2SO4-based device yields a high gravimetric energy density of 11.4 Wh/kg. Particularly, the ion-diffusion highways in porous carbon nanosheets contribute to the 2.25 V LiTFSI-based symmetric device with a high energy delivery up to 33.1 Wh/kg. This work offers an inspiring strategy for facile fabrication of carbon nanosheets, and demonstrates their promising application in "water-in-salt" electrolyte-based supercapacitor systems.
A facile fabrication strategy is reported to obtain N/O codoped porous carbon nanosheets for purpose of ameliorating the charge transfer and accumulation in the concentrated LiTFSI (lithium bis(trifluoromethane sulfonyl)imide) electrolyte. By tunning the feed ratio of comonomers, the porous nanosheet structure is endowed with a significant ion-adsorption surface area (1630 m2/g) and interconnected hierarchical porosity; meanwhile, high-level N/O dopants (N: 3.58 at%, O: 12.91 at%) increase the effective contact area for electrolyte ions, and further facilitate rapid ion/electron transfer. Benefiting from the advantageous features, carbon nanosheets electrode reveal an enhanced specific capacitance (375 F/g) in three-electrode configuration and the H2SO4-based device yields a high gravimetric energy density of 11.4 Wh/kg. Particularly, the ion-diffusion highways in porous carbon nanosheets contribute to the 2.25 V LiTFSI-based symmetric device with a high energy delivery up to 33.1 Wh/kg. This work offers an inspiring strategy for facile fabrication of carbon nanosheets, and demonstrates their promising application in "water-in-salt" electrolyte-based supercapacitor systems.
2022, 33(5): 2687-2691
doi: 10.1016/j.cclet.2021.09.076
Abstract:
Alcohol fuels oxidation plays a significant role in carbon sustainable cycling and high-performance catalyst with a strong anti-poisoning effect is desired. Herein, Pt-Ni alloy supported on the N-doped graphene aerogel synthesized by simple freeze-drying and annealing was demonstrated to have such catalytic ability for alcohol fuel oxidation. Pt-Ni alloy particles were found uniformly dispersed over the surface of 3D N-doped graphene aerogel. High anti-poisoning ability for CO-like intermediates oxidation was demonstrated by the CO-stripping experiment. The as-prepared catalyst was found to have outstanding catalytic performance for methanol and ethanol oxidation with high catalytic activity, stability and catalytic kinetics. Compared to the control samples, the improved catalytic ability could be due to the presence of oxophilic Ni species and the support effect of 3D N-doped graphene aerogel that combined multi-advantages of large surface area, facile mass transfer, and abundant defects.
Alcohol fuels oxidation plays a significant role in carbon sustainable cycling and high-performance catalyst with a strong anti-poisoning effect is desired. Herein, Pt-Ni alloy supported on the N-doped graphene aerogel synthesized by simple freeze-drying and annealing was demonstrated to have such catalytic ability for alcohol fuel oxidation. Pt-Ni alloy particles were found uniformly dispersed over the surface of 3D N-doped graphene aerogel. High anti-poisoning ability for CO-like intermediates oxidation was demonstrated by the CO-stripping experiment. The as-prepared catalyst was found to have outstanding catalytic performance for methanol and ethanol oxidation with high catalytic activity, stability and catalytic kinetics. Compared to the control samples, the improved catalytic ability could be due to the presence of oxophilic Ni species and the support effect of 3D N-doped graphene aerogel that combined multi-advantages of large surface area, facile mass transfer, and abundant defects.
2022, 33(5): 2692-2696
doi: 10.1016/j.cclet.2021.09.107
Abstract:
We herein proposed a sample introduction technique based on solution cathode glow discharge (SCGD) of a portable design for inductively coupled plasma-optical emission spectrometry (ICP-OES) and its application in sensitive determination of mercury. The products from SCGD containing mercury vapor, were transported by an Ar flow to ICP spectrometer for detection. A gas liquid separator (GLS) and a dryer were used to condense and remove most of the accompanying moisture, which greatly improved both the stability and sensitivity of the signal. The detection limit (DL) acquired by this developed method was 0.22 µg/L (194.1 nm), which was nearly 82 times lower than that obtained by pneumatic nebulization (PN). The relative standard deviation (RSD) was 1.4% (n = 14) for a 50 µg/L standard. Blank solution (HNO3, pH 1) can effectively elute mercury residue. Its accuracy and practicality were also demonstrated by the determination of GBW10029 (fish) certified reference material, shrimp, crawfish, soil and human hair samples. The results showed good consistency with the certified values and the values obtained using inductively coupled plasma−mass spectrometry.
We herein proposed a sample introduction technique based on solution cathode glow discharge (SCGD) of a portable design for inductively coupled plasma-optical emission spectrometry (ICP-OES) and its application in sensitive determination of mercury. The products from SCGD containing mercury vapor, were transported by an Ar flow to ICP spectrometer for detection. A gas liquid separator (GLS) and a dryer were used to condense and remove most of the accompanying moisture, which greatly improved both the stability and sensitivity of the signal. The detection limit (DL) acquired by this developed method was 0.22 µg/L (194.1 nm), which was nearly 82 times lower than that obtained by pneumatic nebulization (PN). The relative standard deviation (RSD) was 1.4% (n = 14) for a 50 µg/L standard. Blank solution (HNO3, pH 1) can effectively elute mercury residue. Its accuracy and practicality were also demonstrated by the determination of GBW10029 (fish) certified reference material, shrimp, crawfish, soil and human hair samples. The results showed good consistency with the certified values and the values obtained using inductively coupled plasma−mass spectrometry.
2022, 33(5): 2697-2700
doi: 10.1016/j.cclet.2021.08.122
Abstract:
Droplet-based microfluidic technology can be utilized as a microreactor to prepare novel functional monodisperse microcapsules. In this study, a droplet-based microfluidic chip with surface modification, which allowed the one-step preparation of double emulsion microcapsules. An O/W/O double emulsion using polyethylene (glycol) diacrylate (PEGDA) solution as the intermediate water phase was prepared by regulating the hydrophilicity and hydrophobicity of the chip surface, with PEGDA microcapsules prepared using UV polymerization. And then anti-tumor drug paclitaxel and neurotoxin 6-OHDA were encapsulated in microcapsules for drug and toxicology evaluation, respectively. Compared to controls, drug-loaded microcapsules caused a significant increase in the death rate of PC12 cells. This indicates that the obtained drug-loaded microcapsules could be used in drug evaluation and potentially in drug screening and delivery.
Droplet-based microfluidic technology can be utilized as a microreactor to prepare novel functional monodisperse microcapsules. In this study, a droplet-based microfluidic chip with surface modification, which allowed the one-step preparation of double emulsion microcapsules. An O/W/O double emulsion using polyethylene (glycol) diacrylate (PEGDA) solution as the intermediate water phase was prepared by regulating the hydrophilicity and hydrophobicity of the chip surface, with PEGDA microcapsules prepared using UV polymerization. And then anti-tumor drug paclitaxel and neurotoxin 6-OHDA were encapsulated in microcapsules for drug and toxicology evaluation, respectively. Compared to controls, drug-loaded microcapsules caused a significant increase in the death rate of PC12 cells. This indicates that the obtained drug-loaded microcapsules could be used in drug evaluation and potentially in drug screening and delivery.
2022, 33(5): 2701-2704
doi: 10.1016/j.cclet.2021.08.128
Abstract:
Tumor heterogeneity plays a critical role in the determination of appropriate anticancer therapy. As circulating tumor cells (CTCs) contain all tumor-related information, the genetic changes on CTCs could help us choose the appropriate treatments for different patients. Single-base mutations are very common in tumor genetic changes which may result in drug resistance. Here, we introduce a single-cell mutation detection platform based on droplet microfluidics. This platform integrates cell capsulation, cell lysis, polymerase chain reaction (PCR) and the observation process. The droplets' generation speed is over 6000 per minute and more than 600 cells could be encapsulated in one second. To verify the performance of our platform in practical use, we performed the mutation analysis of 4 kinds of cells with our platform and noted that the genetic status of each single cell was clearly discriminated. Moreover, these results agreed with those from direct sequencing. Compared with other forms of single-cell mutation detection techniques, our platform has high throughput, short experimental time and less experimental operations.
Tumor heterogeneity plays a critical role in the determination of appropriate anticancer therapy. As circulating tumor cells (CTCs) contain all tumor-related information, the genetic changes on CTCs could help us choose the appropriate treatments for different patients. Single-base mutations are very common in tumor genetic changes which may result in drug resistance. Here, we introduce a single-cell mutation detection platform based on droplet microfluidics. This platform integrates cell capsulation, cell lysis, polymerase chain reaction (PCR) and the observation process. The droplets' generation speed is over 6000 per minute and more than 600 cells could be encapsulated in one second. To verify the performance of our platform in practical use, we performed the mutation analysis of 4 kinds of cells with our platform and noted that the genetic status of each single cell was clearly discriminated. Moreover, these results agreed with those from direct sequencing. Compared with other forms of single-cell mutation detection techniques, our platform has high throughput, short experimental time and less experimental operations.
2022, 33(5): 2705-2707
doi: 10.1016/j.cclet.2021.09.074
Abstract:
Cell migration proceeds in 3D matrices in vivo, which can naturally switch to distinct phenotypes for better invasion in confined microenvironments. The studies of important metabolites under confinement are extremely meaningful for comprehensive insights into cancer metastasis. The integration of cell confinement device and analytical techniques is a key point for in-situ analysis of significant metabolites in vitro. Herein, an electrochemiluminescence (ECL) sensing platform was designed for in-situ monitoring of cell-secreted lactate in highly confined microenvironments. The 3-µm confiner was exactly fabricated via microfabrication and microfluidics technique, and cells in high confinement and low adhesion tended to be round with contractile blebs on cell margins. Significantly, in-situ monitoring of lactate was successfully achieved on the ECL platform with the catalysis of lactate oxidase, in which the levels in different time intervals were acquired in the luminol-hydrogen peroxide system. Furthermore, the results were verified by the liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology, which showed similar fluctuations with the ECL platform. This system offered an available avenue for metabolites analysis in highly confined microenvironments, which may advance deeper insights into metabolic mechanisms of cancer metastasis
Cell migration proceeds in 3D matrices in vivo, which can naturally switch to distinct phenotypes for better invasion in confined microenvironments. The studies of important metabolites under confinement are extremely meaningful for comprehensive insights into cancer metastasis. The integration of cell confinement device and analytical techniques is a key point for in-situ analysis of significant metabolites in vitro. Herein, an electrochemiluminescence (ECL) sensing platform was designed for in-situ monitoring of cell-secreted lactate in highly confined microenvironments. The 3-µm confiner was exactly fabricated via microfabrication and microfluidics technique, and cells in high confinement and low adhesion tended to be round with contractile blebs on cell margins. Significantly, in-situ monitoring of lactate was successfully achieved on the ECL platform with the catalysis of lactate oxidase, in which the levels in different time intervals were acquired in the luminol-hydrogen peroxide system. Furthermore, the results were verified by the liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology, which showed similar fluctuations with the ECL platform. This system offered an available avenue for metabolites analysis in highly confined microenvironments, which may advance deeper insights into metabolic mechanisms of cancer metastasis
2022, 33(5): 2708-2710
doi: 10.1016/j.cclet.2021.08.119
Abstract:
Salinity tolerance of ambient electric arc ionization (AEAI) was evaluated by comparing electrospray ionization for various samples at NaCl concentrations from 0 to 1000 mmol/L. AEAI-mass spectrometry (AEAI-MS) exhibited an excellent signal intensity even at NaCl concentrations of 1000 mmol/L, while the ESI-MS had no signal because high salinity has a strong inhibitory effect on analytes. The sodium adduct was verified using LiCl instead of NaCl. AEAI-MS successfully quantified saline samples with an excellent quantitative ability (R2 ≥ 0.998). We also achieved some analytical samples in the buffer solution at a very high concentration and even in a saturated salt solution. Overall, AEAI-MS has protonated ions for most target analytes. In addition, the relationship between auxiliary temperature and the distance from the sample to the arc was investigated, and the results indicated that thermal desorption plays an important role in AEAI source.
Salinity tolerance of ambient electric arc ionization (AEAI) was evaluated by comparing electrospray ionization for various samples at NaCl concentrations from 0 to 1000 mmol/L. AEAI-mass spectrometry (AEAI-MS) exhibited an excellent signal intensity even at NaCl concentrations of 1000 mmol/L, while the ESI-MS had no signal because high salinity has a strong inhibitory effect on analytes. The sodium adduct was verified using LiCl instead of NaCl. AEAI-MS successfully quantified saline samples with an excellent quantitative ability (R2 ≥ 0.998). We also achieved some analytical samples in the buffer solution at a very high concentration and even in a saturated salt solution. Overall, AEAI-MS has protonated ions for most target analytes. In addition, the relationship between auxiliary temperature and the distance from the sample to the arc was investigated, and the results indicated that thermal desorption plays an important role in AEAI source.
2022, 33(5): 2711-2714
doi: 10.1016/j.cclet.2021.09.020
Abstract:
DNA-based logic gates promote the development of molecular computing and show enormous potential in the fields of nanotechnology and biotechnology. Dumbbell oligonucleotides (DNA) with poly-thymine (poly-T) loops and a nicked random double strand have been demonstrated to be an efficient template for the formation of fluorescent copper nanoclusters (CuNCs) in our previous work. Herein, a new platform technology is presented with which to construct molecular logic gates by employing CuNCs probe as a basic output generator, coupling of functional nucleases as the inputs. Two dumbbell DNAs are used with the difference in stem length (8 bp and 16 bp, respectively). The degradation of DNA templates can be tuned by various nucleic acid enzymes, single-stranded nuclease (S1), double-stranded specific nuclease (DSN), E. coli DNA ligase, exonucleases Ⅰ and Ⅲ. Briefly, S1 can digest both DNA templates, while the cleavage ability of DSN will be resistant by the short stem of SS-DNA (short-stem DNA). Exonuclease Ⅰ and Ⅲ can degrade these two nicked DNA templates, which are inhibited due to the ligation of E. coli DNA ligase. With this novel strategy, a set of logic gates is successfully constructed at the molecular level, including "YES", "PASS 0", "OR", "INHIBIT", which take the advantages of no label, easy operation, fast speed, high efficiency and low cost. Furthermore, S1 nuclease, as the biomarker of numerous carcinogens, is selectively detected in the range of 0.05–50 U/mL with the detection limit of 0.005 U/mL (1 × 10−6 U) based on this platform.
DNA-based logic gates promote the development of molecular computing and show enormous potential in the fields of nanotechnology and biotechnology. Dumbbell oligonucleotides (DNA) with poly-thymine (poly-T) loops and a nicked random double strand have been demonstrated to be an efficient template for the formation of fluorescent copper nanoclusters (CuNCs) in our previous work. Herein, a new platform technology is presented with which to construct molecular logic gates by employing CuNCs probe as a basic output generator, coupling of functional nucleases as the inputs. Two dumbbell DNAs are used with the difference in stem length (8 bp and 16 bp, respectively). The degradation of DNA templates can be tuned by various nucleic acid enzymes, single-stranded nuclease (S1), double-stranded specific nuclease (DSN), E. coli DNA ligase, exonucleases Ⅰ and Ⅲ. Briefly, S1 can digest both DNA templates, while the cleavage ability of DSN will be resistant by the short stem of SS-DNA (short-stem DNA). Exonuclease Ⅰ and Ⅲ can degrade these two nicked DNA templates, which are inhibited due to the ligation of E. coli DNA ligase. With this novel strategy, a set of logic gates is successfully constructed at the molecular level, including "YES", "PASS 0", "OR", "INHIBIT", which take the advantages of no label, easy operation, fast speed, high efficiency and low cost. Furthermore, S1 nuclease, as the biomarker of numerous carcinogens, is selectively detected in the range of 0.05–50 U/mL with the detection limit of 0.005 U/mL (1 × 10−6 U) based on this platform.
2022, 33(5): 2715-2720
doi: 10.1016/j.cclet.2021.08.110
Abstract:
Supraparticles (SPs), such as assembly of inorganic components with organic, have made tremendous attention in biochemical analysis, which represents a novel but challenging research orientation. Herein, a single-SPs multifunctional fluorescent sensor array has been developed for high-throughput detection of heavy metal ions in biofluids, which is based on an inorganic/organic hybrid SPs consisting of carbon dots (CDs) and an easily available porphyrin [5, 10, 15, 20-tetra(4-carboxyphenyl)porphyrin (TCPP)]. TCPP can aggregate with the CDs to form the assembly (CDs/TCPP SPs) through the electrostatic and π-π stacking interaction. There are two independent and clearly separated fluorescence emission peaks at 470 and 668 nm in the resultant CDs/TCPP SPs under 380 nm excitation. As a proof-of concept design, F470, F668, F668/F470 of SPs are chosen as three sensor components to constitute our sensor array. With the addition of metal ions, three sensor components can generate different fluorescence response patterns for discriminating 11 heavy metal ions via principal component analysis (PCA). Additionally, thiols can readily capture Cu2+ to switch the fluorescence of CDs/TCPP initially altered by Cu2+. Hence, CDs/TCPP-Cu2+ ensemble is further demonstrated to be a powerful sensor array for pattern recognition of 7 thiols and even chiral recognition of cysteine enantiomers. This novel strategy avoids the tanglesome synthesis of multiple sensing probes and dedicates an innovative method for the facile establishment of tongue-mimic sensors, which would prospectively sprout more homologous assumptions to broaden its application toward more biosensing fields.
Supraparticles (SPs), such as assembly of inorganic components with organic, have made tremendous attention in biochemical analysis, which represents a novel but challenging research orientation. Herein, a single-SPs multifunctional fluorescent sensor array has been developed for high-throughput detection of heavy metal ions in biofluids, which is based on an inorganic/organic hybrid SPs consisting of carbon dots (CDs) and an easily available porphyrin [5, 10, 15, 20-tetra(4-carboxyphenyl)porphyrin (TCPP)]. TCPP can aggregate with the CDs to form the assembly (CDs/TCPP SPs) through the electrostatic and π-π stacking interaction. There are two independent and clearly separated fluorescence emission peaks at 470 and 668 nm in the resultant CDs/TCPP SPs under 380 nm excitation. As a proof-of concept design, F470, F668, F668/F470 of SPs are chosen as three sensor components to constitute our sensor array. With the addition of metal ions, three sensor components can generate different fluorescence response patterns for discriminating 11 heavy metal ions via principal component analysis (PCA). Additionally, thiols can readily capture Cu2+ to switch the fluorescence of CDs/TCPP initially altered by Cu2+. Hence, CDs/TCPP-Cu2+ ensemble is further demonstrated to be a powerful sensor array for pattern recognition of 7 thiols and even chiral recognition of cysteine enantiomers. This novel strategy avoids the tanglesome synthesis of multiple sensing probes and dedicates an innovative method for the facile establishment of tongue-mimic sensors, which would prospectively sprout more homologous assumptions to broaden its application toward more biosensing fields.
2022, 33(5): 2721-2725
doi: 10.1016/j.cclet.2021.08.126
Abstract:
A class of silica anchored Schiff base decorated polyamidoamine (PAMAM) dendrimers were synthesized for removing aqueous Cu(Ⅱ) and Ag(Ⅰ). The adsorption performance was investigated synthetically and the adsorption mechanism was revealed. Results indicate the adsorption capacity depends on dendrimer generation, solution pH, contact time, temperature and initial metal ion concentration. The optimum adsorption pH is 6 for both metal ion. Adsorption kinetic suggests the adsorption can achieve equilibrium at 180 and 150 min for Cu(Ⅱ) and Ag(Ⅰ). The kinetic process is found to be in good agreement with pseudo-second-order model and film diffusion is the rate-controlling step. The adsorption isotherm indicates the adsorption is proceeded by monolayer behavior with chemical mechanism. These adsorbents exhibit competitive adsorption capacity as compared with other reported adsorbents. Theoretical calculation demonstrates the participation of hydroxyl, carbonyl, and amide groups during the adsorption of Cu(Ⅱ), while hydroxyl and amide groups are mainly responsible for capturing Ag(Ⅰ).
A class of silica anchored Schiff base decorated polyamidoamine (PAMAM) dendrimers were synthesized for removing aqueous Cu(Ⅱ) and Ag(Ⅰ). The adsorption performance was investigated synthetically and the adsorption mechanism was revealed. Results indicate the adsorption capacity depends on dendrimer generation, solution pH, contact time, temperature and initial metal ion concentration. The optimum adsorption pH is 6 for both metal ion. Adsorption kinetic suggests the adsorption can achieve equilibrium at 180 and 150 min for Cu(Ⅱ) and Ag(Ⅰ). The kinetic process is found to be in good agreement with pseudo-second-order model and film diffusion is the rate-controlling step. The adsorption isotherm indicates the adsorption is proceeded by monolayer behavior with chemical mechanism. These adsorbents exhibit competitive adsorption capacity as compared with other reported adsorbents. Theoretical calculation demonstrates the participation of hydroxyl, carbonyl, and amide groups during the adsorption of Cu(Ⅱ), while hydroxyl and amide groups are mainly responsible for capturing Ag(Ⅰ).
2022, 33(5): 2726-2730
doi: 10.1016/j.cclet.2021.09.006
Abstract:
The temperature of waste gas in refuse transfer station, airport smoking area, and RTO terminal is low, which needs deep oxidation. Catalytic ozonation is one of the most effective treatment techniques in these scenarios. In this study, we reported that catalysts were modified under the condition of magnetic field to simulate the low temperature dynamic conditions of low concentration toluene for catalytic ozonation. This paper aims to explore the relationship between oxygen vacancy and active oxygen species, and the specific pathways of toluene oxidation. The study found that citric acid can enhance the synergistic effect between Mn and Ce, and promote the generation of oxygen vacancies. The surface molecule adsorption oxygen is more conducive to catalytic oxidation than subsurface atom adsorption oxygen. Finally, we proposed the main pathways of toluene in this reaction system, which runs through the whole process of the reaction.
The temperature of waste gas in refuse transfer station, airport smoking area, and RTO terminal is low, which needs deep oxidation. Catalytic ozonation is one of the most effective treatment techniques in these scenarios. In this study, we reported that catalysts were modified under the condition of magnetic field to simulate the low temperature dynamic conditions of low concentration toluene for catalytic ozonation. This paper aims to explore the relationship between oxygen vacancy and active oxygen species, and the specific pathways of toluene oxidation. The study found that citric acid can enhance the synergistic effect between Mn and Ce, and promote the generation of oxygen vacancies. The surface molecule adsorption oxygen is more conducive to catalytic oxidation than subsurface atom adsorption oxygen. Finally, we proposed the main pathways of toluene in this reaction system, which runs through the whole process of the reaction.
Contribution of redox-active properties of compost-derived humic substances in hematite bioreduction
2022, 33(5): 2731-2735
doi: 10.1016/j.cclet.2021.08.115
Abstract:
The compost-derived humic substances (HS) can function as electron mediators for promoting hematite bioreduction because of its redox capacity. Humification process can affect redox capacities of compost-derived HS by changing its intrinsic structure. However, the redox properties of compost-derived HS linking with hematite bioreduction during composting still remain unclear. Herein, we investigated the redox capacities of compost-derived HS, and assessed the responses of the redox capacities to the hematite bioreduction. The result showed that compost-derived HS (i.e., humic acids (HA) and fulvic acids (FA)) were able to accept electrons from Shewanella oneidensis MR-1, and the electron accepting capacity was increased during composting. Furthermore, it could be functioned as electron mediators for promoting the hematite bioreduction, achieving 1.19-2.15 times compared with the control experience. Not only the aromatic structures (quinone) but also the non-quinone structures such as nitrogen- and sulfur-containing functional moieties were served as the redox-active functional groups of compost-derived HS. Our work proved that the aromatic functional groups and the heteroatom structures (especially N) were important to the hematite bioreduction. This study highlights the redox-active properties of compost-derived HS and its impact on the microbial reduction of iron mineral. Redox capacity of compost-derived HS might mitigate the environmental risk of contaminants when the composting production was added into the contaminated soils as low-cost repair materials
The compost-derived humic substances (HS) can function as electron mediators for promoting hematite bioreduction because of its redox capacity. Humification process can affect redox capacities of compost-derived HS by changing its intrinsic structure. However, the redox properties of compost-derived HS linking with hematite bioreduction during composting still remain unclear. Herein, we investigated the redox capacities of compost-derived HS, and assessed the responses of the redox capacities to the hematite bioreduction. The result showed that compost-derived HS (i.e., humic acids (HA) and fulvic acids (FA)) were able to accept electrons from Shewanella oneidensis MR-1, and the electron accepting capacity was increased during composting. Furthermore, it could be functioned as electron mediators for promoting the hematite bioreduction, achieving 1.19-2.15 times compared with the control experience. Not only the aromatic structures (quinone) but also the non-quinone structures such as nitrogen- and sulfur-containing functional moieties were served as the redox-active functional groups of compost-derived HS. Our work proved that the aromatic functional groups and the heteroatom structures (especially N) were important to the hematite bioreduction. This study highlights the redox-active properties of compost-derived HS and its impact on the microbial reduction of iron mineral. Redox capacity of compost-derived HS might mitigate the environmental risk of contaminants when the composting production was added into the contaminated soils as low-cost repair materials
2022, 33(5): 2736-2740
doi: 10.1016/j.cclet.2021.08.107
Abstract:
Donor-acceptor (D-A) conjugated polymers are widely used in photovoltaic applications and heterogeneous catalysis due to their tunable building block and pre-designable structures. Here, a series of adjustable Donor-acceptor (D-A) benzothiodiazole-based conjugated polymers were designed and synthesized. The photocatalytic performance could be improved by fine-tuning the chemical structure by halogen substitution (F or Cl). The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes, as well as promoting the oxidative coupling of benzylamines. Complete degradation of RhB and MO occurred in 30 min under visible light radiation, while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%. Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers. Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.
Donor-acceptor (D-A) conjugated polymers are widely used in photovoltaic applications and heterogeneous catalysis due to their tunable building block and pre-designable structures. Here, a series of adjustable Donor-acceptor (D-A) benzothiodiazole-based conjugated polymers were designed and synthesized. The photocatalytic performance could be improved by fine-tuning the chemical structure by halogen substitution (F or Cl). The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes, as well as promoting the oxidative coupling of benzylamines. Complete degradation of RhB and MO occurred in 30 min under visible light radiation, while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%. Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers. Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.
2022, 33(5): 2741-2746
doi: 10.1016/j.cclet.2021.08.099
Abstract:
Due to the massive discharge of antibiotics in water, it is an urgent matter to remove antibiotics from waste water. The photocatalysts with high stability and activity have attracted extensive attention from researchers. By an in-situ polymerization method, polypyrrole (PPy) was modified on the surface of TiO2 (named as TiO2/PPy). By one-step reduction method, NiCoP was grafted on the surface of TiO2/PPy (named as TiO2/PPy/NiCoP) to synthesize the photocatalyst of TiO2/PPy/NiCoP for degradation of tetracycline (TC) antibiotic. The characterization results revealed that NiCoP was deposited on the surface of TiO2/PPy successfully. The photocatalytic experiment results illustrated that 83.2% of TC could be degraded at natural pH with 20 mg of TiO2/PPy/NiCoP in 50 mL of TC solution (10 mg/L) under visible light irradiation. The high catalytic activity is attributed to the attachment of NiCoP on the surface of TiO2/PPy which can enlarge the light response range of TiO2 effectively. Scavenger studies revealed that the degradation of TC was dominated by ·O2- and h+. The photodegradation efficiency of TC with TiO2/PPy/NiCoP still reached over 74% after 5 consecutive cycles, indicating the potential applications in practical wastewater.
Due to the massive discharge of antibiotics in water, it is an urgent matter to remove antibiotics from waste water. The photocatalysts with high stability and activity have attracted extensive attention from researchers. By an in-situ polymerization method, polypyrrole (PPy) was modified on the surface of TiO2 (named as TiO2/PPy). By one-step reduction method, NiCoP was grafted on the surface of TiO2/PPy (named as TiO2/PPy/NiCoP) to synthesize the photocatalyst of TiO2/PPy/NiCoP for degradation of tetracycline (TC) antibiotic. The characterization results revealed that NiCoP was deposited on the surface of TiO2/PPy successfully. The photocatalytic experiment results illustrated that 83.2% of TC could be degraded at natural pH with 20 mg of TiO2/PPy/NiCoP in 50 mL of TC solution (10 mg/L) under visible light irradiation. The high catalytic activity is attributed to the attachment of NiCoP on the surface of TiO2/PPy which can enlarge the light response range of TiO2 effectively. Scavenger studies revealed that the degradation of TC was dominated by ·O2- and h+. The photodegradation efficiency of TC with TiO2/PPy/NiCoP still reached over 74% after 5 consecutive cycles, indicating the potential applications in practical wastewater.
2022, 33(5): 2747-2752
doi: 10.1016/j.cclet.2021.10.086
Abstract:
Catalytic potential of carbon nanomaterials in peroxydisulfate (PDS) advanced oxidation systems for degradation of antibiotics remains poorly understood. This study revealed ordered mesoporous carbon (type CMK) acted as a superior catalyst for heterogeneous degradation of sulfadiazine (SDZ) in PDS system, with a first-order reaction kinetic constant (k) and total organic carbon (TOC) mineralization efficiency of 0.06 min-1 and 59.67% ± 3.4% within 60 min, respectively. CMK catalyzed PDS system exhibited high degradation efficiencies of five other sulfonamides and three other types of antibiotics, verifying the broad-degradation capacity of antibiotics. Under neutral pH conditions, the optimal catalytic parameters were an initial SDZ concentration of 44.0 mg/L, CMK dosage of 0.07 g/L, and PDS dosage of 5.44 mmol/L, respectively. X-ray photoelectron spectroscopy and Raman spectrum analysis confirmed that the defect structure at edge of CMK and oxygen-containing functional groups on surface of CMK were major active sites, contributing to the high catalytic activity. Free radical quenching analysis revealed that both SO4·- and ·OH were generated and participated in catalytic reaction. In addition, direct electron transfer by CMK to activate PDS also occurred, further promoting catalytic performance. Configuration of SDZ molecule was optimized using density functional theory, and the possible reaction sites in SDZ molecule were calculated using Fukui function. Combining ultra-high-performance liquid chromatography (UPLC)–mass spectrometry (MS)/MS analysis, three potential degradation pathways were proposed, including the direct removal of SO2 molecules, the 14S-17 N fracture, and the 19C-20 N and 19C-27 N cleavage of the SDZ molecule. The study demonstrated that ordered mesoporous carbon could work as a feasible catalytic material for PDS advanced oxidation during removal of antibiotics from wastewater.
Catalytic potential of carbon nanomaterials in peroxydisulfate (PDS) advanced oxidation systems for degradation of antibiotics remains poorly understood. This study revealed ordered mesoporous carbon (type CMK) acted as a superior catalyst for heterogeneous degradation of sulfadiazine (SDZ) in PDS system, with a first-order reaction kinetic constant (k) and total organic carbon (TOC) mineralization efficiency of 0.06 min-1 and 59.67% ± 3.4% within 60 min, respectively. CMK catalyzed PDS system exhibited high degradation efficiencies of five other sulfonamides and three other types of antibiotics, verifying the broad-degradation capacity of antibiotics. Under neutral pH conditions, the optimal catalytic parameters were an initial SDZ concentration of 44.0 mg/L, CMK dosage of 0.07 g/L, and PDS dosage of 5.44 mmol/L, respectively. X-ray photoelectron spectroscopy and Raman spectrum analysis confirmed that the defect structure at edge of CMK and oxygen-containing functional groups on surface of CMK were major active sites, contributing to the high catalytic activity. Free radical quenching analysis revealed that both SO4·- and ·OH were generated and participated in catalytic reaction. In addition, direct electron transfer by CMK to activate PDS also occurred, further promoting catalytic performance. Configuration of SDZ molecule was optimized using density functional theory, and the possible reaction sites in SDZ molecule were calculated using Fukui function. Combining ultra-high-performance liquid chromatography (UPLC)–mass spectrometry (MS)/MS analysis, three potential degradation pathways were proposed, including the direct removal of SO2 molecules, the 14S-17 N fracture, and the 19C-20 N and 19C-27 N cleavage of the SDZ molecule. The study demonstrated that ordered mesoporous carbon could work as a feasible catalytic material for PDS advanced oxidation during removal of antibiotics from wastewater.
2022, 33(5): 2753-2756
doi: 10.1016/j.cclet.2021.11.013
Abstract:
Monitoring of ambient volatile organic compounds (VOCs) was conducted within typical residential-commercial area in the city of Xi'an in northwest China during typical ozone (O3) episodes, to investigate the major contributors to the characteristic of ambient VOCs and their impact on O3 production. In the residential-commercial area, diurnal variation of VOCs was highly impacted by vehicle exhaust, fuel evaporation, and local solvent use. Relative higher contributions (up to 60%) of VOCs from solvent use to the ozone formation potential were found. The present findings highlight the urgent need for restrictions on the emission of VOCs from solvent use and non-vehicle-traffic-related sources, such as oil storage.
Monitoring of ambient volatile organic compounds (VOCs) was conducted within typical residential-commercial area in the city of Xi'an in northwest China during typical ozone (O3) episodes, to investigate the major contributors to the characteristic of ambient VOCs and their impact on O3 production. In the residential-commercial area, diurnal variation of VOCs was highly impacted by vehicle exhaust, fuel evaporation, and local solvent use. Relative higher contributions (up to 60%) of VOCs from solvent use to the ozone formation potential were found. The present findings highlight the urgent need for restrictions on the emission of VOCs from solvent use and non-vehicle-traffic-related sources, such as oil storage.
2022, 33(5): 2757-2762
doi: 10.1016/j.cclet.2021.08.121
Abstract:
Monovalent cation perm-selective membrane (MCPMs) allow fast and selective transport of monovalent cations, and they are promisingly required for extraction of special ions, such as lithium extraction, acid recovery and sea salt production. Herein, we report a novel strategy to design the critical functional layers of MCPMs with both space charge repulsion and cross-linked dense screenability. The in-situ deposition polymerization of pyrrole was carried out on the surface of sulfonated polyphenyl sulfone (SPPSU) substrate membrane followed by cross-linking quaternization of the polypyrrole (PPy) layer with diiodinated functional molecules, thus, the membrane obtained more excellent selective permeability and stable transport properties of monovalent cations. It confirms that the designed PPy layers with charged surface and cross-linking structure improved the hydrophilicity, facilitated cation transport and increased ion flux. Meanwhile, for the dense PPy layer, the charged cross-linked structure endowed the functional layer with the synergistic characteristics of Donnan exclusion and pore size sieving for positively charged ions, which improved the monovalent cation perm-selectivity of the membranes. At a constant current density of 5.1 mA/cm2, the optimal membrane exhibited superior perm-selectivity (PMgNa) and monovalent cation flux (JNa+ = 2.80×10 -8 mol cm-2 s-1) during electrodialysis.
Monovalent cation perm-selective membrane (MCPMs) allow fast and selective transport of monovalent cations, and they are promisingly required for extraction of special ions, such as lithium extraction, acid recovery and sea salt production. Herein, we report a novel strategy to design the critical functional layers of MCPMs with both space charge repulsion and cross-linked dense screenability. The in-situ deposition polymerization of pyrrole was carried out on the surface of sulfonated polyphenyl sulfone (SPPSU) substrate membrane followed by cross-linking quaternization of the polypyrrole (PPy) layer with diiodinated functional molecules, thus, the membrane obtained more excellent selective permeability and stable transport properties of monovalent cations. It confirms that the designed PPy layers with charged surface and cross-linking structure improved the hydrophilicity, facilitated cation transport and increased ion flux. Meanwhile, for the dense PPy layer, the charged cross-linked structure endowed the functional layer with the synergistic characteristics of Donnan exclusion and pore size sieving for positively charged ions, which improved the monovalent cation perm-selectivity of the membranes. At a constant current density of 5.1 mA/cm2, the optimal membrane exhibited superior perm-selectivity (PMgNa) and monovalent cation flux (JNa+ = 2.80×10 -8 mol cm-2 s-1) during electrodialysis.
2022, 33(5): 2517-2521
doi: 10.1016/j.cclet.2021.11.090
Abstract:
Osteoporosis (OP) is a noncommunicable bone disease caused by a shift in the balance between osteoblasts and osteoclasts, and can severely affect the health of elderly persons. Autologous stem-cell transplantation can improve reduced bone density and weakened fracture healing abilities in patients with OP. However, OP can adversely affect the osteogenesis and proliferation abilities of autologous adipose-derived stem cells (ASCs). Therefore, an effective drug is required to facilitate autologous ASCs to recover their osteogenic and proliferative potential. Tetrahedral framework nucleic acid (tFNA) is a new type of nanomaterial that has ability to regulate the biological behavior of cells effectively and enhance the bioactivity of stem cells. In this study, we examine the effects of tFNAs on the osteogenic differentiation and proliferation abilities of ASCs in rats with OP. The results indicate that the 250 nmol/L tFNAs can considerably increase the expression of osteogenesis-related markers, effectively promote the proliferation and osteogenic differentiation of osteoporotic ASCs (OP-ASCs), and help them to regain their osteogenic and proliferative potential. In short, tFNAs can enable OP-ACSs to recover their osteogenic potential and promote their proliferation and, therefore, can play a key regulatory role in autologous ASC transplantation.
Osteoporosis (OP) is a noncommunicable bone disease caused by a shift in the balance between osteoblasts and osteoclasts, and can severely affect the health of elderly persons. Autologous stem-cell transplantation can improve reduced bone density and weakened fracture healing abilities in patients with OP. However, OP can adversely affect the osteogenesis and proliferation abilities of autologous adipose-derived stem cells (ASCs). Therefore, an effective drug is required to facilitate autologous ASCs to recover their osteogenic and proliferative potential. Tetrahedral framework nucleic acid (tFNA) is a new type of nanomaterial that has ability to regulate the biological behavior of cells effectively and enhance the bioactivity of stem cells. In this study, we examine the effects of tFNAs on the osteogenic differentiation and proliferation abilities of ASCs in rats with OP. The results indicate that the 250 nmol/L tFNAs can considerably increase the expression of osteogenesis-related markers, effectively promote the proliferation and osteogenic differentiation of osteoporotic ASCs (OP-ASCs), and help them to regain their osteogenic and proliferative potential. In short, tFNAs can enable OP-ACSs to recover their osteogenic potential and promote their proliferation and, therefore, can play a key regulatory role in autologous ASC transplantation.
2022, 33(5): 2522-2526
doi: 10.1016/j.cclet.2021.12.030
Abstract:
Developing phosphors with long-lifetime (millisecond scale or even longer) solid state room temperature phosphorescence (RTP) feature has attracted considerable attention. However, to date, stimuli-responsive phosphors with RTP nature are still rare due to the absence of effective guidelines for the exploitation of luminophors synchronously possessing stimuli-responsive and RTP characteristics. In this work, a series of mononuclear gold(I) complexes are reported. All these complexes exhibit various solid-state RTP properties, and phosphor 1-Cl exhibits long-lived RTP behavior. The effect of halogen atoms on the RTP nature of these complexes is investigated in detail. Furthermore, the introduction of different types of halogen atoms can effectively regulate the phosphorescent mechanochromism phenomena of these gold(I)-containing complexes. In addition, these phosphors display typical aggregation-induced emission (AIE) effect except for phosphor 5-CCl, which lacks hydrogen-bonding interactions compared with the other four phosphors. This work will be very helpful to the development of mechanical-force-responsive AIE phosphors with lasting RTP.
Developing phosphors with long-lifetime (millisecond scale or even longer) solid state room temperature phosphorescence (RTP) feature has attracted considerable attention. However, to date, stimuli-responsive phosphors with RTP nature are still rare due to the absence of effective guidelines for the exploitation of luminophors synchronously possessing stimuli-responsive and RTP characteristics. In this work, a series of mononuclear gold(I) complexes are reported. All these complexes exhibit various solid-state RTP properties, and phosphor 1-Cl exhibits long-lived RTP behavior. The effect of halogen atoms on the RTP nature of these complexes is investigated in detail. Furthermore, the introduction of different types of halogen atoms can effectively regulate the phosphorescent mechanochromism phenomena of these gold(I)-containing complexes. In addition, these phosphors display typical aggregation-induced emission (AIE) effect except for phosphor 5-CCl, which lacks hydrogen-bonding interactions compared with the other four phosphors. This work will be very helpful to the development of mechanical-force-responsive AIE phosphors with lasting RTP.
2022, 33(5): 2527-2531
doi: 10.1016/j.cclet.2021.11.080
Abstract:
Glutathione (GSH) is a key maintainer of cellular redox balance and plays an important role in many physiological effects. For example, GSH has been widely implicated in cancer initiation, progression and metastasis. Moreover, the concentrations of GSH in tumor cells can influence drug resistance. Given the serious harmfulness of cancer and the important roles of GSH in cancer, it has great significance to development probes for screening of tumor cells and real-time monitoring of GSH fluctuations in tumor cells. However, no targetable probe for reversible imaging of GSH in tumor cells has been reported. Herein, we constructed a melatonin-based targetable and reversible fluorescent probe (GR-MT) for screening of tumor cells and real-time imaging of GSH fluctuations in tumor cells. The probe uses coumarin as the skeleton, Michael addition reaction as the reaction mechanism, and melatonin as the targeted groups of tumor cells. The experimental results demonstrate this probe has many advantages including high selectivity, satisfactory sensitivity, excellent reversible ability, rapid reaction speed, and outstanding targetability of tumor cells. Therefore, this study provides a promising tool for tumor cells screening and real-time detection of GSH fluctuations in specific tumor cells.
Glutathione (GSH) is a key maintainer of cellular redox balance and plays an important role in many physiological effects. For example, GSH has been widely implicated in cancer initiation, progression and metastasis. Moreover, the concentrations of GSH in tumor cells can influence drug resistance. Given the serious harmfulness of cancer and the important roles of GSH in cancer, it has great significance to development probes for screening of tumor cells and real-time monitoring of GSH fluctuations in tumor cells. However, no targetable probe for reversible imaging of GSH in tumor cells has been reported. Herein, we constructed a melatonin-based targetable and reversible fluorescent probe (GR-MT) for screening of tumor cells and real-time imaging of GSH fluctuations in tumor cells. The probe uses coumarin as the skeleton, Michael addition reaction as the reaction mechanism, and melatonin as the targeted groups of tumor cells. The experimental results demonstrate this probe has many advantages including high selectivity, satisfactory sensitivity, excellent reversible ability, rapid reaction speed, and outstanding targetability of tumor cells. Therefore, this study provides a promising tool for tumor cells screening and real-time detection of GSH fluctuations in specific tumor cells.
2022, 33(5): 2532-2536
doi: 10.1016/j.cclet.2021.12.020
Abstract:
Based on three rationally designed pyrrole-appended o-carborane derivatives, we present that fluorescence properties of crystalline materials are highly dependent on intermolecular interaction and steric hinderance. Though the three molecules are similar in structure, single crystals of the three compounds showed obvious difference in molecular stacking and fluorescence behavior. Systematic studies indicate that fluorescence quantum yields, thermo-response as well as mechano-response are highly dependent on intermolecular interaction and steric hindrance. In the three crystalline materials, the CB-NMe crystals with weaker intermolecular interaction and looser molecular packing showed superior fluorescence quantum yield and temperature sensitivity. Accordingly, surface temperature detection strip with favorable reversibility is prepared by doping CB-NMe into the polymer. In addition, the CB-NMe aggregates can be used for monitoring bovine serum albumin (BSA) denaturation, as temperature response of the aggregates can be reversed when co-assembled with BSA.
Based on three rationally designed pyrrole-appended o-carborane derivatives, we present that fluorescence properties of crystalline materials are highly dependent on intermolecular interaction and steric hinderance. Though the three molecules are similar in structure, single crystals of the three compounds showed obvious difference in molecular stacking and fluorescence behavior. Systematic studies indicate that fluorescence quantum yields, thermo-response as well as mechano-response are highly dependent on intermolecular interaction and steric hindrance. In the three crystalline materials, the CB-NMe crystals with weaker intermolecular interaction and looser molecular packing showed superior fluorescence quantum yield and temperature sensitivity. Accordingly, surface temperature detection strip with favorable reversibility is prepared by doping CB-NMe into the polymer. In addition, the CB-NMe aggregates can be used for monitoring bovine serum albumin (BSA) denaturation, as temperature response of the aggregates can be reversed when co-assembled with BSA.
2022, 33(5): 2537-2540
doi: 10.1016/j.cclet.2021.11.082
Abstract:
To test the hypothesis that the microviscosity changes of Endoplasmic Reticulum (ER) can be a useful indicator of ferroptosis promoted by ER Stresses (ERS), a new ER targeting viscosity rotor, L-Vis-1 was developed and applied in the quantitation of viscosity by FLIM imaging in live cells. The FLIM imaging exhibited an excellent resolution almost as good as the corresponding confocal imaging, more significantly, during ferroptosis processes promoted by different types of ERS, the viscosity increases were clearly monitored by FLIM of L-Vis-1 within ER, which has not been demonstrated before.
To test the hypothesis that the microviscosity changes of Endoplasmic Reticulum (ER) can be a useful indicator of ferroptosis promoted by ER Stresses (ERS), a new ER targeting viscosity rotor, L-Vis-1 was developed and applied in the quantitation of viscosity by FLIM imaging in live cells. The FLIM imaging exhibited an excellent resolution almost as good as the corresponding confocal imaging, more significantly, during ferroptosis processes promoted by different types of ERS, the viscosity increases were clearly monitored by FLIM of L-Vis-1 within ER, which has not been demonstrated before.
