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2022 Volume 33 Issue 3
2022, 33(3): 1117-1130
doi: 10.1016/j.cclet.2021.07.034
Abstract:
Considering the significant importance in both ecological and environmental fields, converting nitrogen oxide (NOx, especially NO) into value-added NH3 or harmless N2 lies in the core of research over the past decades. Exploring catalyst for related gas molecular activation and highly efficient reaction systems operated under low temperature or even mild conditions are the key issues. Enormous efforts have been devoted to NO removal by utilizing various driving forces, such as thermal, electrical or solar energy, which shine light on the way to achieve satisfying conversion efficiency. Herein, we will review the state-of-the-art catalysts for NO removal driven by the above-mentioned energies, including a comprehensive introduction and discussion on the pathway and mechanism of each reaction, and the recent achievements of catalysts on each aspect. Particularly, the progress of NO removal by environmentally friendly photocatalysis and electrocatalysis methods will be highlighted. The challenges and opportunities in the future research on the current topic will be discussed as well.
Considering the significant importance in both ecological and environmental fields, converting nitrogen oxide (NOx, especially NO) into value-added NH3 or harmless N2 lies in the core of research over the past decades. Exploring catalyst for related gas molecular activation and highly efficient reaction systems operated under low temperature or even mild conditions are the key issues. Enormous efforts have been devoted to NO removal by utilizing various driving forces, such as thermal, electrical or solar energy, which shine light on the way to achieve satisfying conversion efficiency. Herein, we will review the state-of-the-art catalysts for NO removal driven by the above-mentioned energies, including a comprehensive introduction and discussion on the pathway and mechanism of each reaction, and the recent achievements of catalysts on each aspect. Particularly, the progress of NO removal by environmentally friendly photocatalysis and electrocatalysis methods will be highlighted. The challenges and opportunities in the future research on the current topic will be discussed as well.
2022, 33(3): 1131-1140
doi: 10.1016/j.cclet.2021.09.026
Abstract:
As a biologically active macromolecule, deoxyribonucleic acid (DNA) has the advantages of sequence programmability and structure controllability and can accurately transmit sequence information to specific biological functions. Facing the complex internal microenvironment and heterogeneity in tumor treatment, the construction and applications of DNA-based nanomaterials have become a focus point of research. In particular, the hybridization of DNA molecules with other materials endows DNA-based nanomaterials with multiple functions such as targeting, stimulus responsiveness and regulations of biological activities, making DNA nanostructures great potential in the treatment of major human diseases. In this review, the construction and characteristics of DNA-based nanomaterials are introduced. Then, the functions and applications of DNA-based nanomaterials in the delivery of chemotherapy drugs and gene drugs, stimulus-responsive release and regulation of cell homeostasis are reviewed. Finally, the future development and challenges of DNA-based nanomaterials are prospected. We envision that DNA-based nanomaterials can enrich the nanomaterial system by rational design and synthesis and address the growing demands on biological and biomedical applications in the real world.
As a biologically active macromolecule, deoxyribonucleic acid (DNA) has the advantages of sequence programmability and structure controllability and can accurately transmit sequence information to specific biological functions. Facing the complex internal microenvironment and heterogeneity in tumor treatment, the construction and applications of DNA-based nanomaterials have become a focus point of research. In particular, the hybridization of DNA molecules with other materials endows DNA-based nanomaterials with multiple functions such as targeting, stimulus responsiveness and regulations of biological activities, making DNA nanostructures great potential in the treatment of major human diseases. In this review, the construction and characteristics of DNA-based nanomaterials are introduced. Then, the functions and applications of DNA-based nanomaterials in the delivery of chemotherapy drugs and gene drugs, stimulus-responsive release and regulation of cell homeostasis are reviewed. Finally, the future development and challenges of DNA-based nanomaterials are prospected. We envision that DNA-based nanomaterials can enrich the nanomaterial system by rational design and synthesis and address the growing demands on biological and biomedical applications in the real world.
2022, 33(3): 1141-1153
doi: 10.1016/j.cclet.2021.07.057
Abstract:
Hydrogen energy (H2) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental pollution. Photocatalytic hydrogen evolution (PHE) from water splitting based on semiconductors is a promising technology towards converting solar energy into sustainable H2 fuel evolution. Developing high-activity and abundant source semiconductor materials is particularly important to realize highly efficient hydrogen evolution as for photocatalysis technology. However, unmodified pristine photocatalysts are often unable to overcome the weakness of low performance due to their limitations. In recent years, transition metal phosphides (TMPs) were used as valid co-catalysts to replace the classic precious metal materials in the process of photocatalytic reaction owing to their lower cost and higher combustion heat value. What is more, bimetallic phosphides have been also caused widespread concern in H2 evolution reaction owing to its much lower overpotential, more superior conductivity, and weaker charge carriers transfer impedance in comparison to those of single metal phosphides. In this minireview, we concluded the latest developments of bimetallic phosphides for a series of photocatalytic reactions. Firstly, we briefly summarize the present loading methods of bimetallic phosphides (BMPs) anchored on the photocatalyst. After that, the H2 evolution efficiency based on BMPs as cocatalyst is also studied in detail. Besides, the application of BMPs-based host photocatalyst for H2 evolution under dye sensitization effect has also been discussed. At last, the current development prospects and prospective challenges in many ways of BMPs are proposed. We sincerely hope this minireview has certain reference value for great developments of BMPs in the future research.
Hydrogen energy (H2) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental pollution. Photocatalytic hydrogen evolution (PHE) from water splitting based on semiconductors is a promising technology towards converting solar energy into sustainable H2 fuel evolution. Developing high-activity and abundant source semiconductor materials is particularly important to realize highly efficient hydrogen evolution as for photocatalysis technology. However, unmodified pristine photocatalysts are often unable to overcome the weakness of low performance due to their limitations. In recent years, transition metal phosphides (TMPs) were used as valid co-catalysts to replace the classic precious metal materials in the process of photocatalytic reaction owing to their lower cost and higher combustion heat value. What is more, bimetallic phosphides have been also caused widespread concern in H2 evolution reaction owing to its much lower overpotential, more superior conductivity, and weaker charge carriers transfer impedance in comparison to those of single metal phosphides. In this minireview, we concluded the latest developments of bimetallic phosphides for a series of photocatalytic reactions. Firstly, we briefly summarize the present loading methods of bimetallic phosphides (BMPs) anchored on the photocatalyst. After that, the H2 evolution efficiency based on BMPs as cocatalyst is also studied in detail. Besides, the application of BMPs-based host photocatalyst for H2 evolution under dye sensitization effect has also been discussed. At last, the current development prospects and prospective challenges in many ways of BMPs are proposed. We sincerely hope this minireview has certain reference value for great developments of BMPs in the future research.
2022, 33(3): 1154-1168
doi: 10.1016/j.cclet.2021.07.059
Abstract:
Localized surface plasmon resonance (LSPR) enhanced photocatalysis has fascinated much interest and considerable efforts have been devoted toward the development of plasmonic photocatalysts. In the past decades, noble metal nanoparticles (Au and Ag) with LSPR feature have found wide applications in solar energy conversion. Numerous metal-based photocatalysts have been proposed including metal/semiconductor heterostructures and plasmonic bimetallic or multimetallic nanostructures. However, high cost and scarce reserve of noble metals largely limit their further practical use, which drives the focus gradually shift to low-cost and abundant nonmetallic nanostructures. Recently, various heavily doped semiconductors (such as WO3-x, MoO3-x, Cu2-xS, TiN) have emerged as potential alternatives to costly noble metals for efficient photocatalysis due to their strong LSPR property in visible-near infrared region. This review starts with a brief introduction to LSPR property and LSPR-enhanced photocatalysis, the following highlights recent advances of plasmonic photocatalysts from noble metal to semiconductor-based plasmonic nanostructures. Their synthesis methods and promising applicability in plasmon-driven photocatalytic reactions such as water splitting, CO2 reduction and pollution decomposition are also summarized in details. This review is expected to give guidelines for exploring more efficient plasmonic systems and provide a perspective on development of plasmonic photocatalysis.
Localized surface plasmon resonance (LSPR) enhanced photocatalysis has fascinated much interest and considerable efforts have been devoted toward the development of plasmonic photocatalysts. In the past decades, noble metal nanoparticles (Au and Ag) with LSPR feature have found wide applications in solar energy conversion. Numerous metal-based photocatalysts have been proposed including metal/semiconductor heterostructures and plasmonic bimetallic or multimetallic nanostructures. However, high cost and scarce reserve of noble metals largely limit their further practical use, which drives the focus gradually shift to low-cost and abundant nonmetallic nanostructures. Recently, various heavily doped semiconductors (such as WO3-x, MoO3-x, Cu2-xS, TiN) have emerged as potential alternatives to costly noble metals for efficient photocatalysis due to their strong LSPR property in visible-near infrared region. This review starts with a brief introduction to LSPR property and LSPR-enhanced photocatalysis, the following highlights recent advances of plasmonic photocatalysts from noble metal to semiconductor-based plasmonic nanostructures. Their synthesis methods and promising applicability in plasmon-driven photocatalytic reactions such as water splitting, CO2 reduction and pollution decomposition are also summarized in details. This review is expected to give guidelines for exploring more efficient plasmonic systems and provide a perspective on development of plasmonic photocatalysis.
2022, 33(3): 1169-1179
doi: 10.1016/j.cclet.2021.07.066
Abstract:
Due to the technology limitation and inferior deNOx efficiency of urea selective catalytic reduction (SCR) catalysts at low temperatures, passive NOx adsorber (PNA) for decrease of NOx, CO and hydrocarbons (HCs) during "cold start" of vehicles was proposed to meet the further tighten NOx emission regulations in future. Among them, Pd modified zeolite PNA materials have received more attention because of their excellent NOx storage capacity, anti-poisoning and hydrothermal stability and since Pd/zeolite PNA was proposed, a variety of advanced characterization methods have been applied to investigate its adsorption behavior and structure-performance relationship. The comprehension of the active sites and adsorption chemistry of Pd/zeolite PNA was also significantly improved. However, there are few reviews that systematically summarize the recent progress and application challenges in atomic-level understanding of this material. In this review, we summarized the latest research progress of Pd/zeolite PNA, including active adsorption sites, adsorption mechanism, material physicochemical properties, preparation methods, storage and release performance and structure-performance relationships. In addition, the deactivation challenges faced by Pd/zeolite PNA in practical applications, such as chemical poisoning, high temperature hydrothermal aging deactivation, etc., were also discussed at the micro-level, and some possible effective countermeasures are given. Besides, some possible improvements and research hotspots were put forward, which could be helpful for designing and constructing more efficient PNA materials for meeting the ultra-low NOx emission regulation in the future.
Due to the technology limitation and inferior deNOx efficiency of urea selective catalytic reduction (SCR) catalysts at low temperatures, passive NOx adsorber (PNA) for decrease of NOx, CO and hydrocarbons (HCs) during "cold start" of vehicles was proposed to meet the further tighten NOx emission regulations in future. Among them, Pd modified zeolite PNA materials have received more attention because of their excellent NOx storage capacity, anti-poisoning and hydrothermal stability and since Pd/zeolite PNA was proposed, a variety of advanced characterization methods have been applied to investigate its adsorption behavior and structure-performance relationship. The comprehension of the active sites and adsorption chemistry of Pd/zeolite PNA was also significantly improved. However, there are few reviews that systematically summarize the recent progress and application challenges in atomic-level understanding of this material. In this review, we summarized the latest research progress of Pd/zeolite PNA, including active adsorption sites, adsorption mechanism, material physicochemical properties, preparation methods, storage and release performance and structure-performance relationships. In addition, the deactivation challenges faced by Pd/zeolite PNA in practical applications, such as chemical poisoning, high temperature hydrothermal aging deactivation, etc., were also discussed at the micro-level, and some possible effective countermeasures are given. Besides, some possible improvements and research hotspots were put forward, which could be helpful for designing and constructing more efficient PNA materials for meeting the ultra-low NOx emission regulation in the future.
2022, 33(3): 1180-1192
doi: 10.1016/j.cclet.2021.07.067
Abstract:
Cell is the most basic unit of the morphological structure and life activity of an organism. Learning the composition, structure and function of cells, exploring the life activities of cells and studying the interaction between cells are of great significance for human cognition and control of the life activities of organisms. Therefore, rapid, convenient, inexpensive, high-precision and reliable methods of cell separation and analysis are being developed to obtain accurate information for the study of cytology and pathology. Microfluidic chip is a new emerging technology in recent years. It has a micromanufacturing structure, which can not only realize the precise space-time control of fluid and cells, but also reproduces the three-dimensional dynamic microenvironment of cell growth in the body. In addition, the microfluidic chip has unique microphysical properties and facilitates the integration of microdevices, which provides the possibility of real-time monitoring, continuous culture, separation and enrichment, and even in situ analysis of cells. In this review, we summarized recent advances in the development of different techniques for cell isolation and analysis on microfluidic platforms. Focus was put on biochemical and physical methods for cell separation on microfluidic chips. Subsequent cell analysis depending on fluorescence, Raman, cytomicroscopic imaging, mass spectrometry and electrochemical methods also was remarked. Through analyzing and learning the advantages and disadvantages of different technologies, we hope that microfluidic chips will continue to be improved and expanded for medical and clinical applications.
Cell is the most basic unit of the morphological structure and life activity of an organism. Learning the composition, structure and function of cells, exploring the life activities of cells and studying the interaction between cells are of great significance for human cognition and control of the life activities of organisms. Therefore, rapid, convenient, inexpensive, high-precision and reliable methods of cell separation and analysis are being developed to obtain accurate information for the study of cytology and pathology. Microfluidic chip is a new emerging technology in recent years. It has a micromanufacturing structure, which can not only realize the precise space-time control of fluid and cells, but also reproduces the three-dimensional dynamic microenvironment of cell growth in the body. In addition, the microfluidic chip has unique microphysical properties and facilitates the integration of microdevices, which provides the possibility of real-time monitoring, continuous culture, separation and enrichment, and even in situ analysis of cells. In this review, we summarized recent advances in the development of different techniques for cell isolation and analysis on microfluidic platforms. Focus was put on biochemical and physical methods for cell separation on microfluidic chips. Subsequent cell analysis depending on fluorescence, Raman, cytomicroscopic imaging, mass spectrometry and electrochemical methods also was remarked. Through analyzing and learning the advantages and disadvantages of different technologies, we hope that microfluidic chips will continue to be improved and expanded for medical and clinical applications.
2022, 33(3): 1193-1198
doi: 10.1016/j.cclet.2021.08.043
Abstract:
Selective functionalization of C–F bonds in trifluoromethyl groups has recently received a growing interest, as it offers atom- and step-economic pathways to access highly valuable mono- and difluoroalkyl-substituted organic molecules using simple and inexpensive trifluoromethyl sources as the starting materials. In this regard, impressive progress has been made on the defluorinative functionalization reactions that proceed via radical intermediates. Nevertheless, it is still a great challenge to precisely control the defluorination process, due to the continuous decrease of the C–F bond strength after the replacement of one or two fluorine atoms with various functionalities. This review article is aimed to provide a brief overview of recently reported methods used to functionalize C–F bonds of CF3 groups via radical intermediates. An emphasis is placed on the discussion of mechanistic aspects and synthetic applications
Selective functionalization of C–F bonds in trifluoromethyl groups has recently received a growing interest, as it offers atom- and step-economic pathways to access highly valuable mono- and difluoroalkyl-substituted organic molecules using simple and inexpensive trifluoromethyl sources as the starting materials. In this regard, impressive progress has been made on the defluorinative functionalization reactions that proceed via radical intermediates. Nevertheless, it is still a great challenge to precisely control the defluorination process, due to the continuous decrease of the C–F bond strength after the replacement of one or two fluorine atoms with various functionalities. This review article is aimed to provide a brief overview of recently reported methods used to functionalize C–F bonds of CF3 groups via radical intermediates. An emphasis is placed on the discussion of mechanistic aspects and synthetic applications
2022, 33(3): 1199-1206
doi: 10.1016/j.cclet.2021.08.067
Abstract:
Oximes derivatives have been vastly used in organic synthesis. In this review, C(sp3)−H bond functionalization of oximes derivatives via iminyl radical induced 1, 5−hydrogen atom transfer was discussed. According to the different type of products, this review was divided into three parts: (1) C(sp3)−H bond functionalization for C−C bond formation. (2) C(sp3)−H bond functionalization for C−N bond formation. (3) C(sp3)−H bond functionalization for C−S, C−F bond formation.
Oximes derivatives have been vastly used in organic synthesis. In this review, C(sp3)−H bond functionalization of oximes derivatives via iminyl radical induced 1, 5−hydrogen atom transfer was discussed. According to the different type of products, this review was divided into three parts: (1) C(sp3)−H bond functionalization for C−C bond formation. (2) C(sp3)−H bond functionalization for C−N bond formation. (3) C(sp3)−H bond functionalization for C−S, C−F bond formation.
2022, 33(3): 1207-1226
doi: 10.1016/j.cclet.2021.08.112
Abstract:
Ketones are one of the most important classes of organic compounds, and widely present in various pharmacological compounds, biologically active molecules and functional materials. Over the past few decades, transition metal-catalyzed conversion of aldehydes has been found to be a powerful method. With the continuous development in recent years, it has become an efficient and uncomplicated strategy for constructing ketones. There are four major mechanisms for transition metal-catalyzed ketone synthesis from aldehyde: (1) carbonyl-Heck reaction, that is 1, 2-insertion of organometal species to aldehydic C=O double bond, (2) direct insertion of transition metal catalysts to aldehydic C-H bond, (3) aldehyde as acyl radical, (4) aldehyde as carbon radical acceptor. This article summarizes related reports on the transformations of aldehydes to generate corresponding ketones under different reaction conditions.
Ketones are one of the most important classes of organic compounds, and widely present in various pharmacological compounds, biologically active molecules and functional materials. Over the past few decades, transition metal-catalyzed conversion of aldehydes has been found to be a powerful method. With the continuous development in recent years, it has become an efficient and uncomplicated strategy for constructing ketones. There are four major mechanisms for transition metal-catalyzed ketone synthesis from aldehyde: (1) carbonyl-Heck reaction, that is 1, 2-insertion of organometal species to aldehydic C=O double bond, (2) direct insertion of transition metal catalysts to aldehydic C-H bond, (3) aldehyde as acyl radical, (4) aldehyde as carbon radical acceptor. This article summarizes related reports on the transformations of aldehydes to generate corresponding ketones under different reaction conditions.
2022, 33(3): 1227-1235
doi: 10.1016/j.cclet.2021.09.005
Abstract:
The process of selectively introducing a CF3 group into an organic molecule using inexpensive, stable, and solid sodium trifluoromethanesulfinate has rapidly advanced in recent years to become an eco-friendly method used by organic chemists to synthesize various natural and bioactive molecules. This review focuses on advances made within the last five years regarding C–H functionalisation, namely thermochemical C(sp2)–H (thio)trifluoromethylations, photochemical C(sp2)–H trifluoromethylations, and electrochemical C(sp2)–H trifluoromethylations, using Langlois' reagent (NaSO2CF3).
The process of selectively introducing a CF3 group into an organic molecule using inexpensive, stable, and solid sodium trifluoromethanesulfinate has rapidly advanced in recent years to become an eco-friendly method used by organic chemists to synthesize various natural and bioactive molecules. This review focuses on advances made within the last five years regarding C–H functionalisation, namely thermochemical C(sp2)–H (thio)trifluoromethylations, photochemical C(sp2)–H trifluoromethylations, and electrochemical C(sp2)–H trifluoromethylations, using Langlois' reagent (NaSO2CF3).
2022, 33(3): 1236-1244
doi: 10.1016/j.cclet.2021.08.081
Abstract:
Commercial lithium-ion batteries (LIBs) have been widely used in various energy storage systems. However, many unfavorable factors of LIBs have prompted researchers to turn their attention to the development of emerging secondary batteries. Aqueous zinc ion batteries (AZIBs) present some prominent advantages with environmental friendliness, low cost and convenient operation feature. MnO2 electrode is the first to be discovered as promising cathode material. So far, manganese-based oxides have made significant progresses in improving the inherent capacity and energy density. Herein, we summarize comprehensively recent advances of Mn-based compounds as electrode materials for ZIBs. Especially, this review focuses on the design strategies of electrode structures, optimization of the electrochemical performance and the clarification of energy storage mechanisms. Finally, their future research directions and perspective are also proposed.
Commercial lithium-ion batteries (LIBs) have been widely used in various energy storage systems. However, many unfavorable factors of LIBs have prompted researchers to turn their attention to the development of emerging secondary batteries. Aqueous zinc ion batteries (AZIBs) present some prominent advantages with environmental friendliness, low cost and convenient operation feature. MnO2 electrode is the first to be discovered as promising cathode material. So far, manganese-based oxides have made significant progresses in improving the inherent capacity and energy density. Herein, we summarize comprehensively recent advances of Mn-based compounds as electrode materials for ZIBs. Especially, this review focuses on the design strategies of electrode structures, optimization of the electrochemical performance and the clarification of energy storage mechanisms. Finally, their future research directions and perspective are also proposed.
2022, 33(3): 1245-1253
doi: 10.1016/j.cclet.2021.09.027
Abstract:
Quantum dots-hydrogel composites are promising new materials that have attracted extensive attention due to their incomparable biocompatibility and acceptable biodegradability, leading to enormous potential applications for various fields. This review summarizes the recent advances in quantum dots-hydrogel composites with a focus on synthesis methods, including hydrogel gelation in quantum dots (QDs) solution, embedding prepared QDs into hydrogels after gelation, forming QDs in situ within the preformed gel and cross-linking via QDs to form hydrogels. In particularly, biomedical applications as bioimaging, biosensing and drug delivery are also reviewed, followed by a discussion on the inherent challenges of design optimization, biocompatibility and bimodal applications and the prospect of the future development. These results will guide the development of quantum dots-hydrogel composites and provide critical insights to inspire researchers in future.
Quantum dots-hydrogel composites are promising new materials that have attracted extensive attention due to their incomparable biocompatibility and acceptable biodegradability, leading to enormous potential applications for various fields. This review summarizes the recent advances in quantum dots-hydrogel composites with a focus on synthesis methods, including hydrogel gelation in quantum dots (QDs) solution, embedding prepared QDs into hydrogels after gelation, forming QDs in situ within the preformed gel and cross-linking via QDs to form hydrogels. In particularly, biomedical applications as bioimaging, biosensing and drug delivery are also reviewed, followed by a discussion on the inherent challenges of design optimization, biocompatibility and bimodal applications and the prospect of the future development. These results will guide the development of quantum dots-hydrogel composites and provide critical insights to inspire researchers in future.
2022, 33(3): 1381-1384
doi: 10.1016/j.cclet.2021.08.012
Abstract:
Spin-crossover (SCO) complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches. Here, by employing the N, Nʹ-4-dipyridyloxalamide (dpo) ligand, we synthesize two Hofmann-type metal-organic frameworks (MOFs) [Fe(dpo){Ag(CN)2}2]3DMF (1) and [Fe(dpo){Ag(CN)2}2]0.5MeCN2DEF (2), which exhibit guest dependent four-step SCO behaviors with the sequences of LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS3/10HS7/10 → HS and LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS1/4HS3/4 → HS, respectively. Therefore, the incorporation of hydrogen-donating/hydrogen-accepting groups into the Hofmann-type MOFs may effectively explore the multi-step SCO materials by tuning hydrogen-bonding interactions.
Spin-crossover (SCO) complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches. Here, by employing the N, Nʹ-4-dipyridyloxalamide (dpo) ligand, we synthesize two Hofmann-type metal-organic frameworks (MOFs) [Fe(dpo){Ag(CN)2}2]3DMF (1) and [Fe(dpo){Ag(CN)2}2]0.5MeCN2DEF (2), which exhibit guest dependent four-step SCO behaviors with the sequences of LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS3/10HS7/10 → HS and LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS1/4HS3/4 → HS, respectively. Therefore, the incorporation of hydrogen-donating/hydrogen-accepting groups into the Hofmann-type MOFs may effectively explore the multi-step SCO materials by tuning hydrogen-bonding interactions.
2022, 33(3): 1385-1389
doi: 10.1016/j.cclet.2021.08.061
Abstract:
Numerous approaches have been used to modify graphitic carbon nitride (g-C3N4) for improving its photocatalytic activity. In this study, we demonstrated a facial post-calcination method for modified graphitic carbon nitride (g-C3N4-Ar/Air) to direct tuning band structure, i.e., bandgap and positions of conduction band (CB)/valence band (VB), through the control of atmospheric condition without involving any additional elements or metals or semiconductors. The synthesized g-C3N4-Ar/Air could efficiently degrade sulfamethazine (SMT) under simulated solar light, i.e., 99.0% removal of SMT with rate constant k1 = 2.696 h−1 within 1.5 h (4.9 times than pristine g-C3N4). Material characterizations indicated that the damaged/partial-collapsed structure and decreased nanosheet-interlayer distance for g-C3N4-Ar/Air resulted in the shift of band structure due to the denser stacking of pristine g-C3N4 through oxidative exfoliation and planarization by air calcination. In addition, the bandgap of g-C3N4-Ar/Air was slightly shrunk from 2.82 eV (pristine g-C3N4) to 2.79 eV, and the CB was significantly upshifted from −0.44 eV (pristine g-C3N4) to −0.81 eV, suggesting the powerful ability for donating the electrons for O2 to form •O2−. Fukui index (f –) based on theoretical calculation indicated that the sites of SMT molecule with high values, i.e., N9, C4 and C6, preferred to be attacked by •O2− and •OH, which is confirmed by the intermediates' analysis. The tuning method for graphitic carbon nitride provides a simple approach to regulate the charge carrier lifetime then facilitate the utilization efficiency of solar light, which exhibits great potential in efficient removal of emerging organic contaminants from wastewater.
Numerous approaches have been used to modify graphitic carbon nitride (g-C3N4) for improving its photocatalytic activity. In this study, we demonstrated a facial post-calcination method for modified graphitic carbon nitride (g-C3N4-Ar/Air) to direct tuning band structure, i.e., bandgap and positions of conduction band (CB)/valence band (VB), through the control of atmospheric condition without involving any additional elements or metals or semiconductors. The synthesized g-C3N4-Ar/Air could efficiently degrade sulfamethazine (SMT) under simulated solar light, i.e., 99.0% removal of SMT with rate constant k1 = 2.696 h−1 within 1.5 h (4.9 times than pristine g-C3N4). Material characterizations indicated that the damaged/partial-collapsed structure and decreased nanosheet-interlayer distance for g-C3N4-Ar/Air resulted in the shift of band structure due to the denser stacking of pristine g-C3N4 through oxidative exfoliation and planarization by air calcination. In addition, the bandgap of g-C3N4-Ar/Air was slightly shrunk from 2.82 eV (pristine g-C3N4) to 2.79 eV, and the CB was significantly upshifted from −0.44 eV (pristine g-C3N4) to −0.81 eV, suggesting the powerful ability for donating the electrons for O2 to form •O2−. Fukui index (f –) based on theoretical calculation indicated that the sites of SMT molecule with high values, i.e., N9, C4 and C6, preferred to be attacked by •O2− and •OH, which is confirmed by the intermediates' analysis. The tuning method for graphitic carbon nitride provides a simple approach to regulate the charge carrier lifetime then facilitate the utilization efficiency of solar light, which exhibits great potential in efficient removal of emerging organic contaminants from wastewater.
2022, 33(3): 1390-1394
doi: 10.1016/j.cclet.2021.07.036
Abstract:
2D transition metal dichalcogenides (TMDCs) have drawn an enormous amount of attention due to their fascinating properties and application potential in next-generation information process and storage. However, the lack of proper synthesis approach limits their application. Here, we report a controllable synthesis method to grow ultrathin MS2 (M = Ti, Nb, Zr) nanosheets with H2S-assisted chemical vapor deposition (CVD). We found that the presence of H2S plays an important role to control the morphology of nanosheets including the lateral size and the nucleation density. With the assistance of H2S, the growth of MS2 shows much thinner thickness with largely decreased nucleation density, beneficial for the device application, which can be attributed to the kinetics dominated growth. Our method hence opens a new avenue for the CVD growth of 2D TMDCs and the corresponding heterojunction, and paves the way for exploring their intriguing properties and applications.
2D transition metal dichalcogenides (TMDCs) have drawn an enormous amount of attention due to their fascinating properties and application potential in next-generation information process and storage. However, the lack of proper synthesis approach limits their application. Here, we report a controllable synthesis method to grow ultrathin MS2 (M = Ti, Nb, Zr) nanosheets with H2S-assisted chemical vapor deposition (CVD). We found that the presence of H2S plays an important role to control the morphology of nanosheets including the lateral size and the nucleation density. With the assistance of H2S, the growth of MS2 shows much thinner thickness with largely decreased nucleation density, beneficial for the device application, which can be attributed to the kinetics dominated growth. Our method hence opens a new avenue for the CVD growth of 2D TMDCs and the corresponding heterojunction, and paves the way for exploring their intriguing properties and applications.
2022, 33(3): 1395-1402
doi: 10.1016/j.cclet.2021.08.019
Abstract:
Regulation of chemical composition and nanostructure, such as the introduction of dopant into two-dimensional nanomaterials, is a general and valid strategy for the efficient electrocatalyst design. In this work, Co4S3/Co9S8 nanosheets, with an ultrathin layer structure, were successfully synthesized via an efficient solvothermal process combined with ultrasonic exfoliation. Different metal ions (M = Fe3+, Cr3+, Mn2+ and Ni2+) were then doped by a simple cation exchange method and the effects of different dopants on the OER activities of Co4S3/Co9S8 NS were further investigated in alkaline media. The corresponding results implied that M-doped Co4S3/Co9S8 NS (M = Fe3+, Cr3+, Mn2+ and Ni2+) exhibited different electrocatalytic properties. Evidenced by XPS spectra, the different OER activities were mainly aroused by the redistribution of charge at the interface due to an electronic interaction between the doped metal ions and Co4S3/Co9S8 NS.
Regulation of chemical composition and nanostructure, such as the introduction of dopant into two-dimensional nanomaterials, is a general and valid strategy for the efficient electrocatalyst design. In this work, Co4S3/Co9S8 nanosheets, with an ultrathin layer structure, were successfully synthesized via an efficient solvothermal process combined with ultrasonic exfoliation. Different metal ions (M = Fe3+, Cr3+, Mn2+ and Ni2+) were then doped by a simple cation exchange method and the effects of different dopants on the OER activities of Co4S3/Co9S8 NS were further investigated in alkaline media. The corresponding results implied that M-doped Co4S3/Co9S8 NS (M = Fe3+, Cr3+, Mn2+ and Ni2+) exhibited different electrocatalytic properties. Evidenced by XPS spectra, the different OER activities were mainly aroused by the redistribution of charge at the interface due to an electronic interaction between the doped metal ions and Co4S3/Co9S8 NS.
2022, 33(3): 1403-1406
doi: 10.1016/j.cclet.2021.08.033
Abstract:
Formic acid (FA), which can be produced via CO2 reduction and biomass conversion, has received extensive interest as a convenient and safe hydrogen carrier due to its wide range of sources, renewable, high hydrogen content (4.4 wt%), and convenient storage/transportation. Designing highly efficient catalysts is the main challenge to realize the hydrogen production from FA. In this work, well-dispersed and electron-rich PdIr alloy nanoparticles with a size of 1.8 nm are confined in amino-modified 3D mesoporous silica KIT-6 and applied as a highly efficient catalyst for robust hydrogen production from FA at ambient temperature. Small PdIr alloy nanoparticles confined by amino-modified KIT-6 (PdIr/KIT-6-NH2) lead to better catalytic activity compared to that of Pd/KIT-6-NH2 and PdIr confined by bare KIT-6, achieving a high turnover frequency (TOF) value of 3533 h−1 at ambient temperature (303 K), 100% H2 selectivity and conversion toward the dehydrogenation of FA, which is comparable to the best heterogeneous catalysts ever reported. The high catalytic activity of PdIr/KIT-6-NH2 can be attributed to the synergistic effect between Pd and Ir, strong interaction between PdIr and KIT-6-NH2, as well as the amino-groups of KIT-6-NH2 which can act as a proton scavenger to promote the breaking of O-H bond of formic acid.
Formic acid (FA), which can be produced via CO2 reduction and biomass conversion, has received extensive interest as a convenient and safe hydrogen carrier due to its wide range of sources, renewable, high hydrogen content (4.4 wt%), and convenient storage/transportation. Designing highly efficient catalysts is the main challenge to realize the hydrogen production from FA. In this work, well-dispersed and electron-rich PdIr alloy nanoparticles with a size of 1.8 nm are confined in amino-modified 3D mesoporous silica KIT-6 and applied as a highly efficient catalyst for robust hydrogen production from FA at ambient temperature. Small PdIr alloy nanoparticles confined by amino-modified KIT-6 (PdIr/KIT-6-NH2) lead to better catalytic activity compared to that of Pd/KIT-6-NH2 and PdIr confined by bare KIT-6, achieving a high turnover frequency (TOF) value of 3533 h−1 at ambient temperature (303 K), 100% H2 selectivity and conversion toward the dehydrogenation of FA, which is comparable to the best heterogeneous catalysts ever reported. The high catalytic activity of PdIr/KIT-6-NH2 can be attributed to the synergistic effect between Pd and Ir, strong interaction between PdIr and KIT-6-NH2, as well as the amino-groups of KIT-6-NH2 which can act as a proton scavenger to promote the breaking of O-H bond of formic acid.
2022, 33(3): 1407-1411
doi: 10.1016/j.cclet.2021.08.031
Abstract:
Developing all-solid-state polymer electrolytes (SPEs) with high electrochemical performances and stability is of great importance for exploiting of high energy density and safe batteries. Herein, ether linkage and imidazolium ionic liquid (ILs) are incorporated into the multi-armed polymer backbone though the series and parallel way. The parallel polymeric ionic liquid (P-P (PEGMA-IM)) maximizes the synergistic effect of ILs and ether linkage, which endowed the material with low crystallinity and high flame retardancy. The P-P (PEGMA-IM) based P-SPE presents a high ionic conductivity of 0.489 mS/cm at 60 ℃, an excellent lithium-ion transference number of 0.46 and a wide electrochemical window of 4.87 V. The assembled lithium metal battery using P-SPE can deliver a capacity of 151 mAh/g at 0.2 C, and the capacity retention ratio reaches 82% with a columbic efficiency beyond 99%. The overpotential of P-SPE based symmetric battery is 0.08 V, and there is no apparent magnifying even after 130 h cycling. This new design provides a new avenue for exploitation of advanced SPEs for the next-generation batteries.
Developing all-solid-state polymer electrolytes (SPEs) with high electrochemical performances and stability is of great importance for exploiting of high energy density and safe batteries. Herein, ether linkage and imidazolium ionic liquid (ILs) are incorporated into the multi-armed polymer backbone though the series and parallel way. The parallel polymeric ionic liquid (P-P (PEGMA-IM)) maximizes the synergistic effect of ILs and ether linkage, which endowed the material with low crystallinity and high flame retardancy. The P-P (PEGMA-IM) based P-SPE presents a high ionic conductivity of 0.489 mS/cm at 60 ℃, an excellent lithium-ion transference number of 0.46 and a wide electrochemical window of 4.87 V. The assembled lithium metal battery using P-SPE can deliver a capacity of 151 mAh/g at 0.2 C, and the capacity retention ratio reaches 82% with a columbic efficiency beyond 99%. The overpotential of P-SPE based symmetric battery is 0.08 V, and there is no apparent magnifying even after 130 h cycling. This new design provides a new avenue for exploitation of advanced SPEs for the next-generation batteries.
2022, 33(3): 1439-1444
doi: 10.1016/j.cclet.2021.08.063
Abstract:
Morphology-controlled electrocatalysts with the ability of CO2 adsorption/activation, mass transfer, high stability and porosity are much desired in electrochemical CO2 reduction reaction (CO2RR). Here, three kinds of multi-dimensional nanostructures (i.e., hollow sphere, nanosheets and nanofibers) have been successfully produced through the modulation of porphyrin-based covalent organic frameworks (COFs) with various modulators. The obtained nanostructures with high-stability, large surface-area, and single metal sites enable efficient CO2RR into CH4. Notably, they all exhibit higher FE (hollow sphere, 68.2%; nanosheet, 64.2% and nanofiber, 71.0%, −0.9 V) than COF-366-Cu (43.0%, −0.9 V) after morphology control. Noteworthy, the FE of COF-366-Cu (HS) keeps higher than 52.4% over a wide potential range from −0.9 V to −1.1 V and the achieved FECH4+C2H4 (82.8%, −0.9 V) is superior to most of reported COFs and copper-based electrocatalysts. This work paves a new way in the exploration of COF-based multi-dimensional nanostructures applicable in efficient CO2RR to CH4.
Morphology-controlled electrocatalysts with the ability of CO2 adsorption/activation, mass transfer, high stability and porosity are much desired in electrochemical CO2 reduction reaction (CO2RR). Here, three kinds of multi-dimensional nanostructures (i.e., hollow sphere, nanosheets and nanofibers) have been successfully produced through the modulation of porphyrin-based covalent organic frameworks (COFs) with various modulators. The obtained nanostructures with high-stability, large surface-area, and single metal sites enable efficient CO2RR into CH4. Notably, they all exhibit higher FE (hollow sphere, 68.2%; nanosheet, 64.2% and nanofiber, 71.0%, −0.9 V) than COF-366-Cu (43.0%, −0.9 V) after morphology control. Noteworthy, the FE of COF-366-Cu (HS) keeps higher than 52.4% over a wide potential range from −0.9 V to −1.1 V and the achieved FECH4+C2H4 (82.8%, −0.9 V) is superior to most of reported COFs and copper-based electrocatalysts. This work paves a new way in the exploration of COF-based multi-dimensional nanostructures applicable in efficient CO2RR to CH4.
2022, 33(3): 1445-1449
doi: 10.1016/j.cclet.2021.08.051
Abstract:
Here, we report a finding on light-mediated CO2-responsiveness. It is found on the microgels that are made of side-chain type metallopolymers containing metalla-aromatics. Turbidity and laser light scattering studies on dilute aqueous dispersion of these microgels in dark indicate high CO2-responsivity, but poor reversibility upon N2 purge, which can be improved by exposing to light. This light-mediated CO2-responsiveness can be elucidated by the loss of aromaticity from initial photoexcitation and concurrent formation of a less reactive, antiaromatic excited state of relatively low CO2 binding affinity, and by subsequent relief of antiaromaticity that can enhance the CO2 removal. The finding is also checked by CO2 uptake-release experiments on the microgels, which enables both CO2 capture of high capacity and CO2 removal of good reversibility under a mild condition, allowing effective and reversible response to dilute CO2.
Here, we report a finding on light-mediated CO2-responsiveness. It is found on the microgels that are made of side-chain type metallopolymers containing metalla-aromatics. Turbidity and laser light scattering studies on dilute aqueous dispersion of these microgels in dark indicate high CO2-responsivity, but poor reversibility upon N2 purge, which can be improved by exposing to light. This light-mediated CO2-responsiveness can be elucidated by the loss of aromaticity from initial photoexcitation and concurrent formation of a less reactive, antiaromatic excited state of relatively low CO2 binding affinity, and by subsequent relief of antiaromaticity that can enhance the CO2 removal. The finding is also checked by CO2 uptake-release experiments on the microgels, which enables both CO2 capture of high capacity and CO2 removal of good reversibility under a mild condition, allowing effective and reversible response to dilute CO2.
2022, 33(3): 1450-1454
doi: 10.1016/j.cclet.2021.08.062
Abstract:
van der Waals (vdWs) heterostructures based on two-dimensional (2D) materials have become a promising candidate for photoelectrochemical (PEC) catalyst not only because of the freedom in materials design that enable the band-offset construction and facilitate the charge separation. They also provide a platform for the study of various of interface effect in PEC. Here, we report a new kind of mixed-dimensional vdWs heterostructure photoelectrode and investigate the strain enhanced PEC performance at vdWs interfaces. Our heterostructures are composed of 2D n-type MoS2 nanosheets and three-dimensional (3D) p-type Cu2O nanorod arrays (NRAs), where Cu2O NRAs introduce periodically strain in the p-n junction interface. We find a promotion of the HER catalytic activities in heterostructure based PEC photoelectrodes using in-situ measurement techniques including the scanning electrochemical cell microscopy and various local spectrum probe measurements. This is attributed to the efficient charge separation at the strained heterointerface. Our results demonstrate an interesting venue for understanding the local interface effects with high spatial resolution, and shed light on design and developing high-efficiency photoelectrodes. 1L MoS2/Cu2O vdWs heterostructure photocathodes were prepared by nanoindentation technology. The effects of strain on promoting charge separation at the heterointerface were verified by the enhanced performances in PEC hydrogen evolution reaction of vdWs heterostructure through scanning electrochemical cell microscopy technique and various local spectrum probe measurements.
van der Waals (vdWs) heterostructures based on two-dimensional (2D) materials have become a promising candidate for photoelectrochemical (PEC) catalyst not only because of the freedom in materials design that enable the band-offset construction and facilitate the charge separation. They also provide a platform for the study of various of interface effect in PEC. Here, we report a new kind of mixed-dimensional vdWs heterostructure photoelectrode and investigate the strain enhanced PEC performance at vdWs interfaces. Our heterostructures are composed of 2D n-type MoS2 nanosheets and three-dimensional (3D) p-type Cu2O nanorod arrays (NRAs), where Cu2O NRAs introduce periodically strain in the p-n junction interface. We find a promotion of the HER catalytic activities in heterostructure based PEC photoelectrodes using in-situ measurement techniques including the scanning electrochemical cell microscopy and various local spectrum probe measurements. This is attributed to the efficient charge separation at the strained heterointerface. Our results demonstrate an interesting venue for understanding the local interface effects with high spatial resolution, and shed light on design and developing high-efficiency photoelectrodes. 1L MoS2/Cu2O vdWs heterostructure photocathodes were prepared by nanoindentation technology. The effects of strain on promoting charge separation at the heterointerface were verified by the enhanced performances in PEC hydrogen evolution reaction of vdWs heterostructure through scanning electrochemical cell microscopy technique and various local spectrum probe measurements.
2022, 33(3): 1455-1458
doi: 10.1016/j.cclet.2021.08.102
Abstract:
Nitrogen reduction reaction (NRR) is a clean mode of energy conversion and the development of highly efficient NRR electrocatalysts under ambient conditions for industrial application is still a big challenge. Metal-nitrogen-carbon (M-N-C) has emerged as a class of single atom catalyst due to the unique geometric structure, high catalytic activity, and clear selectivity. Herein, we designed a series of dual metal single atom catalysts containing adjacent M-N-C dual active centers (MN4/M'N4-C) as NRR electrocatalysts to uncover the structure-activity relationship. By evaluating structural stability, catalytic activity, and selectivity using density functional theory (DFT) calculations, 5 catalysts, such as CrN4/M'N4-C (M' = Cr, Mn, Fe, Cu and Zn), were determined to exhibit the best NRR catalytic performance with the limiting potential ranging from −0.64 V to −0.62 V. The CrN4 center acted as the main catalytic site and the adjacent M'N4 center could enhance the NRR catalytic activity by modulation effect based on the analysis of the electronic properties including the charge density difference, partial density of states (PDOS), and Bader charge variation. This study offers useful insights on understanding the structure-activity relationship of dual metal single atom catalysts for electrochemical NRR.
Nitrogen reduction reaction (NRR) is a clean mode of energy conversion and the development of highly efficient NRR electrocatalysts under ambient conditions for industrial application is still a big challenge. Metal-nitrogen-carbon (M-N-C) has emerged as a class of single atom catalyst due to the unique geometric structure, high catalytic activity, and clear selectivity. Herein, we designed a series of dual metal single atom catalysts containing adjacent M-N-C dual active centers (MN4/M'N4-C) as NRR electrocatalysts to uncover the structure-activity relationship. By evaluating structural stability, catalytic activity, and selectivity using density functional theory (DFT) calculations, 5 catalysts, such as CrN4/M'N4-C (M' = Cr, Mn, Fe, Cu and Zn), were determined to exhibit the best NRR catalytic performance with the limiting potential ranging from −0.64 V to −0.62 V. The CrN4 center acted as the main catalytic site and the adjacent M'N4 center could enhance the NRR catalytic activity by modulation effect based on the analysis of the electronic properties including the charge density difference, partial density of states (PDOS), and Bader charge variation. This study offers useful insights on understanding the structure-activity relationship of dual metal single atom catalysts for electrochemical NRR.
2022, 33(3): 1459-1462
doi: 10.1016/j.cclet.2021.08.104
Abstract:
Two pairs of Pt(II) enantiomers ((RR)/(SS)-PyPt, ((RR)/(SS)-Py: N, N'-(1, 2-diphenylethane-1, 2-diyl)dipicolinamide; (RR)-P/M-QPt, ((RR)/(SS)-Q: N, N'-((1R, 2R)-1, 2-diphenylethane-1, 2-diyl)bis(quinoline-2-carboxamide)) were synthesized, respectively, with good circularly polarized luminescence (CPL) and tunable dissymmetry factors (g) by molecular self-induction with (RR)/(SS)-1, 2-diphenylethane-1, 2-diamine as carbon chiral sources. In the (RR)-P-QPt and (SS)-M-QPt, specific P- and M-configurations were effectively induced from intrinsic chiral carbon centres (R or S), ingeniously avoiding the racemic mixture formation and chiral separation. Furthermore, the chirality originating from both chiral carbon centres and helicene-like structure improves the g factor significantly, which provides a new molecular design strategy for chiral Pt(II) enantiomers with good CPL properties.
Two pairs of Pt(II) enantiomers ((RR)/(SS)-PyPt, ((RR)/(SS)-Py: N, N'-(1, 2-diphenylethane-1, 2-diyl)dipicolinamide; (RR)-P/M-QPt, ((RR)/(SS)-Q: N, N'-((1R, 2R)-1, 2-diphenylethane-1, 2-diyl)bis(quinoline-2-carboxamide)) were synthesized, respectively, with good circularly polarized luminescence (CPL) and tunable dissymmetry factors (g) by molecular self-induction with (RR)/(SS)-1, 2-diphenylethane-1, 2-diamine as carbon chiral sources. In the (RR)-P-QPt and (SS)-M-QPt, specific P- and M-configurations were effectively induced from intrinsic chiral carbon centres (R or S), ingeniously avoiding the racemic mixture formation and chiral separation. Furthermore, the chirality originating from both chiral carbon centres and helicene-like structure improves the g factor significantly, which provides a new molecular design strategy for chiral Pt(II) enantiomers with good CPL properties.
2022, 33(3): 1463-1467
doi: 10.1016/j.cclet.2021.08.101
Abstract:
Carbon materials hold the great promise for application in energy storage devices owing to their low cost, high thermal/chemical stability, and high electrical conductivity. However, it remains challenging to synthesize high-performance carbon electrodes in a simple, scalable and sustainable way. Here, we report a facile method for scalable synthesis of porous carbon anode by using cheap and easily accessible zeolitic imidazolate framework-8 as a template and polyvinylpyrrolidone as an additional carbon source. The obtained porous carbon shows the macroscopic sheet-like morphology, which has the highly disordered structure, expanded interlayer spacing, abundant pore structure, and nitrogen doping properties. This porous carbon anode is demonstrated to have the excellent K+ charge storage properties in specific capacity, rate capability, and cycling stability. A potassium-ion capacitor assembled by using this porous carbon as the anode, delivers a maximum energy density of 85.12 Wh/kg and power density of 11860 W/kg as well as long cycle life exceeding 3000 cycles. This represents a critical advance in the design of low cost and scalable carbon material for applications in energy storage devices.
Carbon materials hold the great promise for application in energy storage devices owing to their low cost, high thermal/chemical stability, and high electrical conductivity. However, it remains challenging to synthesize high-performance carbon electrodes in a simple, scalable and sustainable way. Here, we report a facile method for scalable synthesis of porous carbon anode by using cheap and easily accessible zeolitic imidazolate framework-8 as a template and polyvinylpyrrolidone as an additional carbon source. The obtained porous carbon shows the macroscopic sheet-like morphology, which has the highly disordered structure, expanded interlayer spacing, abundant pore structure, and nitrogen doping properties. This porous carbon anode is demonstrated to have the excellent K+ charge storage properties in specific capacity, rate capability, and cycling stability. A potassium-ion capacitor assembled by using this porous carbon as the anode, delivers a maximum energy density of 85.12 Wh/kg and power density of 11860 W/kg as well as long cycle life exceeding 3000 cycles. This represents a critical advance in the design of low cost and scalable carbon material for applications in energy storage devices.
2022, 33(3): 1254-1258
doi: 10.1016/j.cclet.2021.08.130
Abstract:
In recent years, the strategy of inhibiting the interactions of p53 with murine double minute 2 (MDM2) and murine double minute X (MDMX) has been proved to be a promising approach for tumor therapy. However, the poor proteolytical stability and low intracellular delivery efficiency of peptide inhibitors limit their clinical application. Here, we designed and synthesized the bicyclic stapled peptides based on p53 by combining all-hydrocarbon stapling and lactam stapling strategies. We demonstrated that bicyclic stapled peptide p53-16 significantly improved α-helicity and proteolytic stability. Especially, p53-16 showed nanomolar binding affinity for MDM2 and MDMX. In addition, p53-16 could penetrate the cell membrane, and selectively inhibited the activity of tumor cells via activating p53 pathway in vitro. Our data suggest that p53-16 is a potential dual inhibitor of MDM2 and MDMX interactions. The bicyclic stapling strategy is a promising drug design strategy for protein–protein interactions inhibitors.
In recent years, the strategy of inhibiting the interactions of p53 with murine double minute 2 (MDM2) and murine double minute X (MDMX) has been proved to be a promising approach for tumor therapy. However, the poor proteolytical stability and low intracellular delivery efficiency of peptide inhibitors limit their clinical application. Here, we designed and synthesized the bicyclic stapled peptides based on p53 by combining all-hydrocarbon stapling and lactam stapling strategies. We demonstrated that bicyclic stapled peptide p53-16 significantly improved α-helicity and proteolytic stability. Especially, p53-16 showed nanomolar binding affinity for MDM2 and MDMX. In addition, p53-16 could penetrate the cell membrane, and selectively inhibited the activity of tumor cells via activating p53 pathway in vitro. Our data suggest that p53-16 is a potential dual inhibitor of MDM2 and MDMX interactions. The bicyclic stapling strategy is a promising drug design strategy for protein–protein interactions inhibitors.
2022, 33(3): 1259-1262
doi: 10.1016/j.cclet.2021.07.065
Abstract:
A novel SrSn(OH)6 photocatalyst with large plate and particle size were synthesized via a facile chemical precipitation method. The photocatalytic activity of the SrSn(OH)6 was evaluated by the removal of NO at ppb level under UV light irradiation. Based on the ESR measurements, SrSn(OH)6 photocatalyst was found to have the ability to generate the main active species of O2•−, •OH and 1O2 during the photocatalytic process. Moreover, SrSn(OH)6 photocatalyst not only exhibits high photocatalytic activity for NO removal (79.6%), but also has good stability after five cycles. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to investigate the NOx transfer pathway and the intermediate products distribution during the adsorption and photocatalytic NO oxidation process. The present work not only provides an efficient material for air pollutants purification at room temperature but also in-depth understanding of the mechanism involved in the photocatalytic NO removal process.
A novel SrSn(OH)6 photocatalyst with large plate and particle size were synthesized via a facile chemical precipitation method. The photocatalytic activity of the SrSn(OH)6 was evaluated by the removal of NO at ppb level under UV light irradiation. Based on the ESR measurements, SrSn(OH)6 photocatalyst was found to have the ability to generate the main active species of O2•−, •OH and 1O2 during the photocatalytic process. Moreover, SrSn(OH)6 photocatalyst not only exhibits high photocatalytic activity for NO removal (79.6%), but also has good stability after five cycles. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to investigate the NOx transfer pathway and the intermediate products distribution during the adsorption and photocatalytic NO oxidation process. The present work not only provides an efficient material for air pollutants purification at room temperature but also in-depth understanding of the mechanism involved in the photocatalytic NO removal process.
2022, 33(3): 1263-1266
doi: 10.1016/j.cclet.2021.07.051
Abstract:
Fabrication of multifunctional nanoplatform to in situ monitor Fenton reaction is of vital importance to probe the underlying reaction process and design high-performance catalyst. Herein, a hybrid catalyst comprising of single-crystalline Au nanoparticles (SC Au NPs) on reduced graphene oxide (RGO) sheet was prepared, which not only exhibited an excellent 1O2 mediated Fenton-like catalytic activity in promoting rhodamine 6G (R6G) degradation by activating H2O2, but also displayed a sensitive surface-enhanced Raman spectroscopy (SERS) detection performance to R6G with a linear response range from 1.0 × 10-8 mol/L to 1.0 × 10-5 mol/L thus providing a powerful and versatile nanoplatform for in situ SERS monitoring Fenton-like catalytic reaction. The integration of catalytic and SERS activities into a single nanostructure are expected to provide great potentials for practical applications in environmental catalysis.
Fabrication of multifunctional nanoplatform to in situ monitor Fenton reaction is of vital importance to probe the underlying reaction process and design high-performance catalyst. Herein, a hybrid catalyst comprising of single-crystalline Au nanoparticles (SC Au NPs) on reduced graphene oxide (RGO) sheet was prepared, which not only exhibited an excellent 1O2 mediated Fenton-like catalytic activity in promoting rhodamine 6G (R6G) degradation by activating H2O2, but also displayed a sensitive surface-enhanced Raman spectroscopy (SERS) detection performance to R6G with a linear response range from 1.0 × 10-8 mol/L to 1.0 × 10-5 mol/L thus providing a powerful and versatile nanoplatform for in situ SERS monitoring Fenton-like catalytic reaction. The integration of catalytic and SERS activities into a single nanostructure are expected to provide great potentials for practical applications in environmental catalysis.
2022, 33(3): 1267-1270
doi: 10.1016/j.cclet.2021.07.049
Abstract:
Magnetic particles (MPs) are the most widely used commercialized engineering particles, which gained great success in various biological applications. Inspired by their intrinsic Fe isotope composition, we discovered a commercialized MPs-internal standard's novel function to realize the accurate quantification of biomolecules. The bioassay of carcinoembryonic antigen (CEA) was chosen as a modal system. The Fe isotope in MPs and Au isotope in report probes were simultaneously and sensitively detected by the elemental mass spectrometry. 197Au/57Fe isotopic ratios and CEA concentrations showed good linearity in the range of 0.6–300 ng/mL, with a detection limit of 0.09 ng/mL (3σ). The accuracy and precision of the proposed MPs-based immunoassay were greatly improved, by eliminating potential MPs loss during magnetic separation and absolute intensity fluctuations. Considering the exceptional availability and universality of commercialized MPs, the proposed method might open a new avenue for MPs' biological applications.
Magnetic particles (MPs) are the most widely used commercialized engineering particles, which gained great success in various biological applications. Inspired by their intrinsic Fe isotope composition, we discovered a commercialized MPs-internal standard's novel function to realize the accurate quantification of biomolecules. The bioassay of carcinoembryonic antigen (CEA) was chosen as a modal system. The Fe isotope in MPs and Au isotope in report probes were simultaneously and sensitively detected by the elemental mass spectrometry. 197Au/57Fe isotopic ratios and CEA concentrations showed good linearity in the range of 0.6–300 ng/mL, with a detection limit of 0.09 ng/mL (3σ). The accuracy and precision of the proposed MPs-based immunoassay were greatly improved, by eliminating potential MPs loss during magnetic separation and absolute intensity fluctuations. Considering the exceptional availability and universality of commercialized MPs, the proposed method might open a new avenue for MPs' biological applications.
2022, 33(3): 1271-1274
doi: 10.1016/j.cclet.2021.07.054
Abstract:
The ability of plasmonic nanostructures to efficiently harvest light energy and generate energetic hot carriers makes them promising materials for utilization in photocatalytic water spitting. Apart from the traditional Au and Ag based plasmonic photocatalysts, more recently the noble–metal–free alternative plasmonic materials have attracted ever–increasing interest. Here we report the first use of plasmonic zirconium nitride (ZrN) nanoparticles as a promising photocatalyst for water splitting. Highly crystalline ZrN nanoparticles with sizes dominating at 30–50 nm were synthesized that exhibit intense visible and near–infrared absorption due to localized surface plasmon resonance (LSPR). Without utilizing any noble metal cocatalysts such as Pt, the plasmonic ZrN nanoparticles alone showed stable photocatalytic activity for H2 evolution in aqueous solution with methanol as sacrificial electron donor. The addition of a cobalt oxide (CoOx) cocatalyst can facilitate the separation of photogenerated charge carriers and further improve the photocatalytic activity. The optimized CoOx modified ZrN photocatalyst was observed not only to activate the O2 evolution reaction with presence of electron acceptor, but also to drive overall water splitting for the simultaneous H2 and O2 evolution in the absence of any sacrificial agents.
The ability of plasmonic nanostructures to efficiently harvest light energy and generate energetic hot carriers makes them promising materials for utilization in photocatalytic water spitting. Apart from the traditional Au and Ag based plasmonic photocatalysts, more recently the noble–metal–free alternative plasmonic materials have attracted ever–increasing interest. Here we report the first use of plasmonic zirconium nitride (ZrN) nanoparticles as a promising photocatalyst for water splitting. Highly crystalline ZrN nanoparticles with sizes dominating at 30–50 nm were synthesized that exhibit intense visible and near–infrared absorption due to localized surface plasmon resonance (LSPR). Without utilizing any noble metal cocatalysts such as Pt, the plasmonic ZrN nanoparticles alone showed stable photocatalytic activity for H2 evolution in aqueous solution with methanol as sacrificial electron donor. The addition of a cobalt oxide (CoOx) cocatalyst can facilitate the separation of photogenerated charge carriers and further improve the photocatalytic activity. The optimized CoOx modified ZrN photocatalyst was observed not only to activate the O2 evolution reaction with presence of electron acceptor, but also to drive overall water splitting for the simultaneous H2 and O2 evolution in the absence of any sacrificial agents.
2022, 33(3): 1275-1278
doi: 10.1016/j.cclet.2021.07.072
Abstract:
This study has demonstrated an interesting amplification effect of magnetic field (MF) on the hydroxylamine (HA)-promoted zero valent iron (ZVI)/H2O2 Fenton-like system. Sulfamethoxazole (SMX) could be efficiently degraded at near neutral pH. Conditional parameters affecting the SMX degradation in the ZVI/H2O2/HA/MF system, e.g., pH and the dosages of ZVI, HA and H2O2, were investigated. Unlike the acid-favorable ZVI/H2O2 and ZVI/H2O2/HA systems, the MF-assisted system exhibited good performances even at pH up to 6.0 and highest degradation rate at pH of 5.0. •OH was still identified as the responsible oxidant. A mechanism involving the MF-enhanced heterogeneous-homogeneous iron cycle was proposed in the near-neutral ZVI/H2O2/HA system. Without MF, HA-induced reductive dissolution of the surface iron oxides occurred and thus leaded to homogeneous Fenton reactions. After the introduction of MF, the gradient magnetic field formed on the ZVI particles would induce the generation of concentration cells of Fe(Ⅱ) and local corrosion of iron. Large amounts of aqueous and bounded Fe(Ⅱ) catalyzed H2O2 to efficiently produce •OH, while HA maintained the surface and bulk cycles of Fe(Ⅱ)/Fe(Ⅲ). The result of study is expected to provide a green, energy-free method in improving the effectiveness of ZVI-based Fenton-like technologies at weak-acidic circumstances.
This study has demonstrated an interesting amplification effect of magnetic field (MF) on the hydroxylamine (HA)-promoted zero valent iron (ZVI)/H2O2 Fenton-like system. Sulfamethoxazole (SMX) could be efficiently degraded at near neutral pH. Conditional parameters affecting the SMX degradation in the ZVI/H2O2/HA/MF system, e.g., pH and the dosages of ZVI, HA and H2O2, were investigated. Unlike the acid-favorable ZVI/H2O2 and ZVI/H2O2/HA systems, the MF-assisted system exhibited good performances even at pH up to 6.0 and highest degradation rate at pH of 5.0. •OH was still identified as the responsible oxidant. A mechanism involving the MF-enhanced heterogeneous-homogeneous iron cycle was proposed in the near-neutral ZVI/H2O2/HA system. Without MF, HA-induced reductive dissolution of the surface iron oxides occurred and thus leaded to homogeneous Fenton reactions. After the introduction of MF, the gradient magnetic field formed on the ZVI particles would induce the generation of concentration cells of Fe(Ⅱ) and local corrosion of iron. Large amounts of aqueous and bounded Fe(Ⅱ) catalyzed H2O2 to efficiently produce •OH, while HA maintained the surface and bulk cycles of Fe(Ⅱ)/Fe(Ⅲ). The result of study is expected to provide a green, energy-free method in improving the effectiveness of ZVI-based Fenton-like technologies at weak-acidic circumstances.
2022, 33(3): 1279-1282
doi: 10.1016/j.cclet.2021.07.053
Abstract:
H2S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO2 and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H2S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu1 catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H2S and SO2 in the tail gas.
H2S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO2 and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H2S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu1 catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H2S and SO2 in the tail gas.
2022, 33(3): 1283-1287
doi: 10.1016/j.cclet.2021.07.060
Abstract:
Exploiting efficient and recyclable photocatalysts is a vital matter for environmental purification. Herein, cerium vanadate (CeVO4) sub-microspheres and silver nanowire (AgNW)@CeVO4 with core-shell architecture as photocatalysts are rationally constructed by hydrothermal approach. The AgNW@CeVO4 photocatalyst obtained by depositing CeVO4 on the surface of Ag NWs possess one dimensional continuous structure, which expand the optical absorption range and reduce the band gap of CeVO4 photocatalyst. Moreover, the resultant AgNW@CeVO4 photocatalyst demonstrates superior photocatalytic performance in the degradation of rhodamine B, methylene blue, and 4-nitrophenol pollutants upon solar light irradiation, compared with pure CeVO4. The excellent photocatalytic activity can be ascribed to the introduction of Ag NWs, which afford rapid charge transport channels and reservoir for the electrons in the AgNW@CeVO4 heterostructure to promote separation of electron–hole pairs. The first-principles investigations reveal increase of adsorption energy of oxygen molecules on the CeVO4 surface with the presence of Ag. Meanwhile, Ag NWs can further improve the photocatalytic efficiency of the AgNW@CeVO4 based on the plasmonic effect. More importantly, the good structural stability and recyclability of AgNW@CeVO4 are observed due to the strong synergistic effect, which ensures long-term usability of photocatalyst and great promise in water purification. This work can offer valuable reference into designs and construction of Ce-based heterojunction photocatalysts for environmental remediation.
Exploiting efficient and recyclable photocatalysts is a vital matter for environmental purification. Herein, cerium vanadate (CeVO4) sub-microspheres and silver nanowire (AgNW)@CeVO4 with core-shell architecture as photocatalysts are rationally constructed by hydrothermal approach. The AgNW@CeVO4 photocatalyst obtained by depositing CeVO4 on the surface of Ag NWs possess one dimensional continuous structure, which expand the optical absorption range and reduce the band gap of CeVO4 photocatalyst. Moreover, the resultant AgNW@CeVO4 photocatalyst demonstrates superior photocatalytic performance in the degradation of rhodamine B, methylene blue, and 4-nitrophenol pollutants upon solar light irradiation, compared with pure CeVO4. The excellent photocatalytic activity can be ascribed to the introduction of Ag NWs, which afford rapid charge transport channels and reservoir for the electrons in the AgNW@CeVO4 heterostructure to promote separation of electron–hole pairs. The first-principles investigations reveal increase of adsorption energy of oxygen molecules on the CeVO4 surface with the presence of Ag. Meanwhile, Ag NWs can further improve the photocatalytic efficiency of the AgNW@CeVO4 based on the plasmonic effect. More importantly, the good structural stability and recyclability of AgNW@CeVO4 are observed due to the strong synergistic effect, which ensures long-term usability of photocatalyst and great promise in water purification. This work can offer valuable reference into designs and construction of Ce-based heterojunction photocatalysts for environmental remediation.
2022, 33(3): 1288-1292
doi: 10.1016/j.cclet.2021.07.061
Abstract:
Despite of the hazardous risk of Pb2+ leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electrochemical oxidation wastewater treatment technique. In this study, a novel Ti/PbO2 anode was fabricated by embedding raw materials that are readily and cheaply available, i.e., hairs. The structure-activity relationship of the new electrode was firstly revealed by material and electrochemical characterizations. Then different levels of pollutants (azo dye, phenol and maleic acid) were used to investigate the electrochemical oxidation performance of the new electrode. Finally, the accelerated electrode lifetime and Pb2+ leakage tests were carried out. Results showed that the embedded hairs changed the preferential crystallographic orientation of PbO2 and decreased the grain size. Hairs introduced additional roughness and active sites, and decreased the electrode impedance, especially under 5 mg/cm2 of embedding amount. The removal efficiencies of different target pollutants were enhanced more or less by embedding appropriate amount of hairs, depending on the current density, but loading excessive hairs had a negative effect. The accumulation of intermediate products during phenol degradation was also changed by the hairs. The new electrode could undergo ~550 h of harsh electrolysis. It is also relieved that the Pb2+ leakage was found to be suppressed during this long-term electrolysis process.
Despite of the hazardous risk of Pb2+ leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electrochemical oxidation wastewater treatment technique. In this study, a novel Ti/PbO2 anode was fabricated by embedding raw materials that are readily and cheaply available, i.e., hairs. The structure-activity relationship of the new electrode was firstly revealed by material and electrochemical characterizations. Then different levels of pollutants (azo dye, phenol and maleic acid) were used to investigate the electrochemical oxidation performance of the new electrode. Finally, the accelerated electrode lifetime and Pb2+ leakage tests were carried out. Results showed that the embedded hairs changed the preferential crystallographic orientation of PbO2 and decreased the grain size. Hairs introduced additional roughness and active sites, and decreased the electrode impedance, especially under 5 mg/cm2 of embedding amount. The removal efficiencies of different target pollutants were enhanced more or less by embedding appropriate amount of hairs, depending on the current density, but loading excessive hairs had a negative effect. The accumulation of intermediate products during phenol degradation was also changed by the hairs. The new electrode could undergo ~550 h of harsh electrolysis. It is also relieved that the Pb2+ leakage was found to be suppressed during this long-term electrolysis process.
2022, 33(3): 1293-1297
doi: 10.1016/j.cclet.2021.08.002
Abstract:
The effects of two solid-based hydrogen peroxides sodium percarbonate (SPC) and calcium peroxide (CP) on waste activated sludge (WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration for the synergistic effect of alkaline and oxidation. The strong alkaline condition led to the leakage of ammonia and the existence of abundant calcium ions accelerated the fixation of phosphorus via precipitation in CP WAS disintegration process. However, the spongy-like layer and low pH condition retarded the release of gaseous ammonia in SPC group. Hydroxyl radical was the main oxygen reactive species in SPC approaches which were more intense than CP by electron spin resonance (ESR) analysis. CP treated WAS contented more small particle size matter and total suspended solids (TSS) increased dramatically. In conclusion, CP pretreated sludge was more suitable for fertilization, while SPC was in favor of anaerobic digestion. This study clarified the differences between these two oxidants and their intermediates on nutrients release in sludge disintegration.
The effects of two solid-based hydrogen peroxides sodium percarbonate (SPC) and calcium peroxide (CP) on waste activated sludge (WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration for the synergistic effect of alkaline and oxidation. The strong alkaline condition led to the leakage of ammonia and the existence of abundant calcium ions accelerated the fixation of phosphorus via precipitation in CP WAS disintegration process. However, the spongy-like layer and low pH condition retarded the release of gaseous ammonia in SPC group. Hydroxyl radical was the main oxygen reactive species in SPC approaches which were more intense than CP by electron spin resonance (ESR) analysis. CP treated WAS contented more small particle size matter and total suspended solids (TSS) increased dramatically. In conclusion, CP pretreated sludge was more suitable for fertilization, while SPC was in favor of anaerobic digestion. This study clarified the differences between these two oxidants and their intermediates on nutrients release in sludge disintegration.
2022, 33(3): 1298-1302
doi: 10.1016/j.cclet.2021.07.055
Abstract:
Metal-free heteroatom doped nanocarbons are promising alternatives to the metal-based materials in catalytic ozonation for destruction of aqueous organic contaminants. In this study, N, S co-doped hollow carbon microspheres (NSCs) were synthesized from the polymerization products during persulfate wet air oxidation of benzothiazole. The contents of doped N and S as well as the structural stability were maneuvered by adjusting the subsequent N2-annealing temperature. Compared with the prevailing single-walled carbon nanotubes, the N2-annealed NSCs demonstrated a higher catalytic ozonation activity for benzimidazole degradation. According to the quantitative structure-activity relationship (QSAR) analysis, the synergistic effect between the graphitic N and the thiophene-S which redistributed the charge distribution of the carbon basal plane contributed to the activity enhancement of the N2-annealed NSCs. Additionally, the hollow structure within the microspheres served as the microreactor to boost the mass transfer and reaction kinetics via the nanoconfinement effects. Quenching and electron paramagnetic resonance (EPR) tests revealed that benzimidazole degradation was dominated by the produced singlet oxygen (1O2) species, while hydroxyl radicals (·OH) were also generated and participated. This study puts forward a novel strategy for synthesis of heteroatom-doped nanocarbons and sheds a light on the relationship between the active sites on the doped nanocarbons and the catalytic performance.
Metal-free heteroatom doped nanocarbons are promising alternatives to the metal-based materials in catalytic ozonation for destruction of aqueous organic contaminants. In this study, N, S co-doped hollow carbon microspheres (NSCs) were synthesized from the polymerization products during persulfate wet air oxidation of benzothiazole. The contents of doped N and S as well as the structural stability were maneuvered by adjusting the subsequent N2-annealing temperature. Compared with the prevailing single-walled carbon nanotubes, the N2-annealed NSCs demonstrated a higher catalytic ozonation activity for benzimidazole degradation. According to the quantitative structure-activity relationship (QSAR) analysis, the synergistic effect between the graphitic N and the thiophene-S which redistributed the charge distribution of the carbon basal plane contributed to the activity enhancement of the N2-annealed NSCs. Additionally, the hollow structure within the microspheres served as the microreactor to boost the mass transfer and reaction kinetics via the nanoconfinement effects. Quenching and electron paramagnetic resonance (EPR) tests revealed that benzimidazole degradation was dominated by the produced singlet oxygen (1O2) species, while hydroxyl radicals (·OH) were also generated and participated. This study puts forward a novel strategy for synthesis of heteroatom-doped nanocarbons and sheds a light on the relationship between the active sites on the doped nanocarbons and the catalytic performance.
2022, 33(3): 1303-1307
doi: 10.1016/j.cclet.2021.07.056
Abstract:
Titanium dioxide (TiO2) has been limited in photocatalysis due to its wide band gap (3.2 eV) and limited absorption in the ultraviolet range. Therefore, organic components have been introduced to hybrid with TiO2 for enhanced photocatalytic efficiency under visible light. Here, we report that benzo[1, 2-b: 4, 5-b']dithiophene polymer was an ideal organic material for the preparation of a hybrid material with TiO2. The energy band gap of the resulting hybrid material decreased to 2.9 eV and the photocatalytic hydrogen production performance reached 745.0 µmol g−1 h−1 under visible light irradiation. Meanwhile, the material still maintained the stability of hydrogen production performance after 40 h of photocatalytic cycles. The analysis of the transient current response and electrochemical impedance revealed that the main reasons for the enhanced water splitting of the hybrid materials were the faster separation of electron hole pairs and the lower recombination of photocarrier ions. Our findings suggest that polythiophene is a promising organic material for exploring hybrid materials with enhanced photocatalytic hydrogen production.
Titanium dioxide (TiO2) has been limited in photocatalysis due to its wide band gap (3.2 eV) and limited absorption in the ultraviolet range. Therefore, organic components have been introduced to hybrid with TiO2 for enhanced photocatalytic efficiency under visible light. Here, we report that benzo[1, 2-b: 4, 5-b']dithiophene polymer was an ideal organic material for the preparation of a hybrid material with TiO2. The energy band gap of the resulting hybrid material decreased to 2.9 eV and the photocatalytic hydrogen production performance reached 745.0 µmol g−1 h−1 under visible light irradiation. Meanwhile, the material still maintained the stability of hydrogen production performance after 40 h of photocatalytic cycles. The analysis of the transient current response and electrochemical impedance revealed that the main reasons for the enhanced water splitting of the hybrid materials were the faster separation of electron hole pairs and the lower recombination of photocarrier ions. Our findings suggest that polythiophene is a promising organic material for exploring hybrid materials with enhanced photocatalytic hydrogen production.
2022, 33(3): 1308-1312
doi: 10.1016/j.cclet.2021.08.006
Abstract:
The regeneration of the injured nerve and recovery of its function have brought attention in the medical field. Electrical stimulation (ES) can enhance the cellular biological behavior and has been widely studied in the treatment of neurological diseases. Microfluidic technology can provide a cell culture platform with the well-controlled environment. Here a novel microfluidic/microelectrode composite microdevice was developed by embedding the microelectrodes to the microfluidic platform, in which microfluidics provided a controlled cell culture platform, and ES promoted the NSCs proliferation. We performed ES on rat neural stem cells (NSCs) to observe the effect on their growth, differentiation, proliferation, and preliminary explored the ES influence on cells in vitro. The results of immunofluorescence showed that ES had no significant effect on the NSCs specific expression, and the NSCs specific expression reached 98.9% ±0.4% after three days of ES. In addition, ES significantly promoted cell growth and the cell proliferation rate reached 49.41%. To conclude, the microfluidic/microelectrode composite microdevice can play a positive role in the nerve injury repair and fundamental research of neurological diseases.
The regeneration of the injured nerve and recovery of its function have brought attention in the medical field. Electrical stimulation (ES) can enhance the cellular biological behavior and has been widely studied in the treatment of neurological diseases. Microfluidic technology can provide a cell culture platform with the well-controlled environment. Here a novel microfluidic/microelectrode composite microdevice was developed by embedding the microelectrodes to the microfluidic platform, in which microfluidics provided a controlled cell culture platform, and ES promoted the NSCs proliferation. We performed ES on rat neural stem cells (NSCs) to observe the effect on their growth, differentiation, proliferation, and preliminary explored the ES influence on cells in vitro. The results of immunofluorescence showed that ES had no significant effect on the NSCs specific expression, and the NSCs specific expression reached 98.9% ±0.4% after three days of ES. In addition, ES significantly promoted cell growth and the cell proliferation rate reached 49.41%. To conclude, the microfluidic/microelectrode composite microdevice can play a positive role in the nerve injury repair and fundamental research of neurological diseases.
2022, 33(3): 1313-1316
doi: 10.1016/j.cclet.2021.07.052
Abstract:
A facile solvo-thermal approach was successfully employed to prepare titanium oxide (TiO2) nano-aggregates with simultaneous copper particles anchoring. The as-synthesized composite could convert CO2 into CH4 and CO products under simulated solar irradiation. The impact of copper loading amounts on the photo-reduction capability was evaluated. It was found proper amount of Cu loading could enhance the activity of CO2 photo-reduction. As a result, the optimal composite (TiO2-Cu-5%) consisting of TiO2 supported with 5% (mole ratio) Cu exhibits 2.2 times higher CH4 yield and 3 times higher CO yield compared with pure TiO2. Conduction band calculated from the band gap and valence X-ray photoelectron spectroscopy (XPS) indicated TiO2 nano-aggregates have suitable band edge alignment with respect to the CO2/CH4 and CO2/CO redox potential. Furthermore, with involving of Cu particles, an efficient separation of photo-generated charges was achieved on the basis of photocurrent response and photoluminescence spectra results, which contributed to the improved photo-catalytic performance. The present work suggested that the Cu-decorated TiO2 could serve as an efficient photo-catalyst for solar-driven CO2 photo-reduction.
A facile solvo-thermal approach was successfully employed to prepare titanium oxide (TiO2) nano-aggregates with simultaneous copper particles anchoring. The as-synthesized composite could convert CO2 into CH4 and CO products under simulated solar irradiation. The impact of copper loading amounts on the photo-reduction capability was evaluated. It was found proper amount of Cu loading could enhance the activity of CO2 photo-reduction. As a result, the optimal composite (TiO2-Cu-5%) consisting of TiO2 supported with 5% (mole ratio) Cu exhibits 2.2 times higher CH4 yield and 3 times higher CO yield compared with pure TiO2. Conduction band calculated from the band gap and valence X-ray photoelectron spectroscopy (XPS) indicated TiO2 nano-aggregates have suitable band edge alignment with respect to the CO2/CH4 and CO2/CO redox potential. Furthermore, with involving of Cu particles, an efficient separation of photo-generated charges was achieved on the basis of photocurrent response and photoluminescence spectra results, which contributed to the improved photo-catalytic performance. The present work suggested that the Cu-decorated TiO2 could serve as an efficient photo-catalyst for solar-driven CO2 photo-reduction.
2022, 33(3): 1317-1320
doi: 10.1016/j.cclet.2021.07.062
Abstract:
Although carbon nanozymes have attracted great interest due to their good biocompatibility, low cost, and high stability, designing high-active carbon nanozymes still faces great challenges. Herein, ultrathin nitrogen-doped carbon nanosheets with rich defects (d-NC) were prepared through a high-temperature annealing process, using potassium chloride and ammonium chloride as templates. Owing to the large specific surface area, rich defects and the high exposure of active sites, the proposed d-NC nanozymes exhibited excellent peroxidase-like activity. The d-NC nanozymes possess maximal reaction velocity and their specific activity is 9.4-fold higher than that of nitrogen-doped carbon nanozymes, indicating that the induced defects can boost the catalytic performance. Benefited from the good peroxidase-like activities of d-NC nanozymes, the colorimetric sensing platforms were constructed for the detection of urease activity and fluoride ion, exhibiting satisfactory stability and selectivity. This study not only offers a way to synthesize carbon nanozymes with improved enzyme-like activities but also broadens their applications in colorimetric biosensing.
Although carbon nanozymes have attracted great interest due to their good biocompatibility, low cost, and high stability, designing high-active carbon nanozymes still faces great challenges. Herein, ultrathin nitrogen-doped carbon nanosheets with rich defects (d-NC) were prepared through a high-temperature annealing process, using potassium chloride and ammonium chloride as templates. Owing to the large specific surface area, rich defects and the high exposure of active sites, the proposed d-NC nanozymes exhibited excellent peroxidase-like activity. The d-NC nanozymes possess maximal reaction velocity and their specific activity is 9.4-fold higher than that of nitrogen-doped carbon nanozymes, indicating that the induced defects can boost the catalytic performance. Benefited from the good peroxidase-like activities of d-NC nanozymes, the colorimetric sensing platforms were constructed for the detection of urease activity and fluoride ion, exhibiting satisfactory stability and selectivity. This study not only offers a way to synthesize carbon nanozymes with improved enzyme-like activities but also broadens their applications in colorimetric biosensing.
2022, 33(3): 1321-1324
doi: 10.1016/j.cclet.2021.07.058
Abstract:
The leaching and non-recoverability of mental ions have always limited the practical application of Fenton-like processes. For the first time, we synthesized molybdenum phosphide (MoP) with dual active sites for the degradation of diclofenac (DCF) in the Fenton-like process. The DCF degradation rate constant (k) of MoP + H2O2 process was calculated to be 0.13 min-1 within 40 min, indicating a highly efficient catalytic ability of MoP. In addition, this catalyst exhibits a stable structure and good activity, which could apply in a broad pH range, different ions solution and real wastewater condition. Accordingly, this efficient catalytic capability may be attributed to the presence of the metal sites Moδ+ and the electron-rich sites Pδ− in MoP, which could induce the generation of hydroxyl radical (·OH) and superoxide radical (·O2−) through electron transfer, resulting in the effective removal of DCF. This study provides an idea for the optimization of Fenton-like technologies and environmental remediation.
The leaching and non-recoverability of mental ions have always limited the practical application of Fenton-like processes. For the first time, we synthesized molybdenum phosphide (MoP) with dual active sites for the degradation of diclofenac (DCF) in the Fenton-like process. The DCF degradation rate constant (k) of MoP + H2O2 process was calculated to be 0.13 min-1 within 40 min, indicating a highly efficient catalytic ability of MoP. In addition, this catalyst exhibits a stable structure and good activity, which could apply in a broad pH range, different ions solution and real wastewater condition. Accordingly, this efficient catalytic capability may be attributed to the presence of the metal sites Moδ+ and the electron-rich sites Pδ− in MoP, which could induce the generation of hydroxyl radical (·OH) and superoxide radical (·O2−) through electron transfer, resulting in the effective removal of DCF. This study provides an idea for the optimization of Fenton-like technologies and environmental remediation.
2022, 33(3): 1325-1330
doi: 10.1016/j.cclet.2021.07.071
Abstract:
Highly dispersed silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 (WZ/SBA-15) as an ordered mesoporous solid acid catalyst was prepared via a facile incipient wetness impregnation (IWI) method that active ingredients, ZrO2 and WO3, were impregnated into the channels of SBA-15 simultaneously with a subsequent calcination process. The relationship between catalyst nature and performance was explored by high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), and FT-IR of pyridine adsorption (Py-IR) characterization techniques. The catalytic performance of W12Z15/SBA-15 is not only greater than that of single component solid acid catalysts, WO3/SBA-15 and ZrO2/SBA-15, but also W12/Z15/SBA-15 prepared by impregnating active ingredients, ZrO2 and WO3, into SBA-15 in sequence. The outstanding performance of W12Z15/SBA-15 is derived from the strong interaction between ZrO2 and WO3, which results in more acid sites, and relatively high specific surface area, large pore volume, and ordered mesoporous structure of SBA-15. The characterization and reaction results clearly demonstrate that the synergy of ZrO2 and WO3 has a clear boost for the alkenylation. The optimized W12Z15/SBA-15-500 achieves a 99.4% conversion of phenylacetylene and a 92.3% selectivity of main product α-arylstyrene for the alkenylation of p-xylene with phenylacetylene, with very low level of oligomers producing at the same time. Moreover, W12Z15/SBA-15-500 shows excellent catalytic stability and regeneration. Therefore, W12Z15/SBA-15-500 is a promising solid acid catalyst for the alkenylation.
Highly dispersed silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 (WZ/SBA-15) as an ordered mesoporous solid acid catalyst was prepared via a facile incipient wetness impregnation (IWI) method that active ingredients, ZrO2 and WO3, were impregnated into the channels of SBA-15 simultaneously with a subsequent calcination process. The relationship between catalyst nature and performance was explored by high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), and FT-IR of pyridine adsorption (Py-IR) characterization techniques. The catalytic performance of W12Z15/SBA-15 is not only greater than that of single component solid acid catalysts, WO3/SBA-15 and ZrO2/SBA-15, but also W12/Z15/SBA-15 prepared by impregnating active ingredients, ZrO2 and WO3, into SBA-15 in sequence. The outstanding performance of W12Z15/SBA-15 is derived from the strong interaction between ZrO2 and WO3, which results in more acid sites, and relatively high specific surface area, large pore volume, and ordered mesoporous structure of SBA-15. The characterization and reaction results clearly demonstrate that the synergy of ZrO2 and WO3 has a clear boost for the alkenylation. The optimized W12Z15/SBA-15-500 achieves a 99.4% conversion of phenylacetylene and a 92.3% selectivity of main product α-arylstyrene for the alkenylation of p-xylene with phenylacetylene, with very low level of oligomers producing at the same time. Moreover, W12Z15/SBA-15-500 shows excellent catalytic stability and regeneration. Therefore, W12Z15/SBA-15-500 is a promising solid acid catalyst for the alkenylation.
2022, 33(3): 1331-1336
doi: 10.1016/j.cclet.2021.07.073
Abstract:
Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H2O2 levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H2O2 from superoxide anion radicals (O2·−) and then ·OH. The combination of GSH elimination and H2O2 elevation boosted the generation of ·OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ·OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.
Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H2O2 levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H2O2 from superoxide anion radicals (O2·−) and then ·OH. The combination of GSH elimination and H2O2 elevation boosted the generation of ·OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ·OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.
2022, 33(3): 1337-1342
doi: 10.1016/j.cclet.2021.08.008
Abstract:
The unique heterojunction photocatalyst of graphite carbon nitride (g-C3N4) modified ultrafine TiO2 (g-C3N4/TiO2) was successfully fabricated by electrochemical etching and co-annealing method. However, the effects of various environmental factors on the degradation of TC by g-C3N4/TiO2 and the internal reaction mechanism are still unclear. In this study, the effects of initial pH, anions, and cations on the photocatalytic degradation of tetracycline hydrochloride (TC) by g-C3N4/TiO2 were systematically explored, and the scavenging experiment and intermediate detection were conducted to better reveal the mechanism on photocatalytic degradation of TC. The results showed that the removal efficiency of photocatalytic degradation of TC by g-C3N4/TiO2 could reach 99.04% under Xenon lamp irradiation within 120 min. The unique g-C3N4/TiO2 heterojunction photocatalyst showed excellent photocatalytic performance for the degradation of TC at pH 3~7, and possesses outstanding anti-interference ability to NO3−, Cl−, Na+, Ca2+ and Mg2+ ions in natural waters during the photocatalytic degradation TC process. Superoxide radicals (O2·−) and hydroxyl radicals (·OH) were proved as the main reactive species for TC degradation, and the possible mechanism of the unique photocatalytic system for g-C3N4/TiO2 was also proposed. The above results can provide a reliable basis and theoretical guidance for the design and application of visible photocatalyst with high activity to degrade the actual wastewater containing TC.
The unique heterojunction photocatalyst of graphite carbon nitride (g-C3N4) modified ultrafine TiO2 (g-C3N4/TiO2) was successfully fabricated by electrochemical etching and co-annealing method. However, the effects of various environmental factors on the degradation of TC by g-C3N4/TiO2 and the internal reaction mechanism are still unclear. In this study, the effects of initial pH, anions, and cations on the photocatalytic degradation of tetracycline hydrochloride (TC) by g-C3N4/TiO2 were systematically explored, and the scavenging experiment and intermediate detection were conducted to better reveal the mechanism on photocatalytic degradation of TC. The results showed that the removal efficiency of photocatalytic degradation of TC by g-C3N4/TiO2 could reach 99.04% under Xenon lamp irradiation within 120 min. The unique g-C3N4/TiO2 heterojunction photocatalyst showed excellent photocatalytic performance for the degradation of TC at pH 3~7, and possesses outstanding anti-interference ability to NO3−, Cl−, Na+, Ca2+ and Mg2+ ions in natural waters during the photocatalytic degradation TC process. Superoxide radicals (O2·−) and hydroxyl radicals (·OH) were proved as the main reactive species for TC degradation, and the possible mechanism of the unique photocatalytic system for g-C3N4/TiO2 was also proposed. The above results can provide a reliable basis and theoretical guidance for the design and application of visible photocatalyst with high activity to degrade the actual wastewater containing TC.
2022, 33(3): 1343-1345
doi: 10.1016/j.cclet.2021.08.022
Abstract:
Herein, we developed a fractionation-free negative enriching method incorporating methylamidation, site-selective dimethylation and aldehyde resin coupling (MADMAR) for in-depth C-terminome analysis. The methylamidation blocked the free carboxyl group on proteins first, followed by LysC digestion of methylamidated proteins. Then, the site-selective dimethylation blocked the N-terminal amino group of the digested peptides without affecting the amino groups of lysine. Finally, the aldehyde resin was used to capture non-C-terminal peptides containing amino groups from lysine, while leaving the C-terminal peptides without free amino group in the supernatant for its analysis. We identified 1359 database-annotated protein C-termini from 50 µg HeLa proteins, which was 74% more than our previous method based on aldehyde resin. Moreover, 279 protein neo-C-termini were identified.
Herein, we developed a fractionation-free negative enriching method incorporating methylamidation, site-selective dimethylation and aldehyde resin coupling (MADMAR) for in-depth C-terminome analysis. The methylamidation blocked the free carboxyl group on proteins first, followed by LysC digestion of methylamidated proteins. Then, the site-selective dimethylation blocked the N-terminal amino group of the digested peptides without affecting the amino groups of lysine. Finally, the aldehyde resin was used to capture non-C-terminal peptides containing amino groups from lysine, while leaving the C-terminal peptides without free amino group in the supernatant for its analysis. We identified 1359 database-annotated protein C-termini from 50 µg HeLa proteins, which was 74% more than our previous method based on aldehyde resin. Moreover, 279 protein neo-C-termini were identified.
2022, 33(3): 1346-1352
doi: 10.1016/j.cclet.2021.08.056
Abstract:
An inexpensive Fe doped aluminoborate consisted of 18% Fe in PKU-1 material that exhibits high selectivity of 4-hydroxymethy-2,2-dimethyl-1,3-dioxolane (Solketal, 98.3%), considerable activity (TOF 51.7 h-1), and recyclable ability in the ketalization of glycerol to Solketal with acetone at 318 K has been developed. Our study demonstrated that the structure of Fe (less agglomerated iron species vs. FeOx clusters) can be tuned by changing Fe loading in the PKU-1 material, which correlated well with experimental observations. Furthermore, the surface boron sites were promoted by iron loading and behaved as Lewis-acid sites to facilitate the reaction process of glycerol ketalization, while the Solketal selectivity was closely related with the structure of iron species in PKU-1, which was proved by kinetic studies, density function theory (DFT) calculations, and a series of spectroscopy studies. This investigation demonstrates that the surface B sites can play important roles in the reaction instead of being spectators.
An inexpensive Fe doped aluminoborate consisted of 18% Fe in PKU-1 material that exhibits high selectivity of 4-hydroxymethy-2,2-dimethyl-1,3-dioxolane (Solketal, 98.3%), considerable activity (TOF 51.7 h-1), and recyclable ability in the ketalization of glycerol to Solketal with acetone at 318 K has been developed. Our study demonstrated that the structure of Fe (less agglomerated iron species vs. FeOx clusters) can be tuned by changing Fe loading in the PKU-1 material, which correlated well with experimental observations. Furthermore, the surface boron sites were promoted by iron loading and behaved as Lewis-acid sites to facilitate the reaction process of glycerol ketalization, while the Solketal selectivity was closely related with the structure of iron species in PKU-1, which was proved by kinetic studies, density function theory (DFT) calculations, and a series of spectroscopy studies. This investigation demonstrates that the surface B sites can play important roles in the reaction instead of being spectators.
2022, 33(3): 1353-1357
doi: 10.1016/j.cclet.2021.08.095
Abstract:
Development of new self-calibrating fluorescent sensing methods has been a popular research field with the aim of protecting the human health and environment sustainability. In this work, a novel Eu-based metal organic framework (MOF) Eu(2,6-NDC)(COO) (BUC-88) was developed by employing 2,6-NDC (2,6-naphthalenedicarboxylic acid) as bridging ligands. BUC-88 performed different sensing process toward quinolone antibiotics and tetracyclines antibiotics in terms of fluorescence intensity and color. BUC-88 exhibited excellent selectivity and sensitivity detection property toward enrofloxacin (ENR), norfloxacin (NOR) and ciprofloxacin (CIP) over other Pharmaceutical and Personal Care Products (PPCPs), accomplishing the detection limit of 0.12 μmol/L, 0.52 μmol/L, 0.75 μmol/L, respectively. Notably, BUC-88 acted as an excellent fluorescence sensor for tetracyclines antibiotics with fast response time (less than 1 s), high selectivity and sensitivity (LODs = 0.08 μmol/L). The fluorescent detection method was successfully used for visual and ultrasensitive detection of ENR, NOR, CIP and tetracycline hydrochloride (TC) in lake water with satisfied recovery from 99.75% to 102.30%. Finally, the photoinduced electron transfer and the competitive absorption of ultraviolet light are the main mechanisms for sensitive detection toward quinolone antibiotics and tetracyclines antibiotics.
Development of new self-calibrating fluorescent sensing methods has been a popular research field with the aim of protecting the human health and environment sustainability. In this work, a novel Eu-based metal organic framework (MOF) Eu(2,6-NDC)(COO) (BUC-88) was developed by employing 2,6-NDC (2,6-naphthalenedicarboxylic acid) as bridging ligands. BUC-88 performed different sensing process toward quinolone antibiotics and tetracyclines antibiotics in terms of fluorescence intensity and color. BUC-88 exhibited excellent selectivity and sensitivity detection property toward enrofloxacin (ENR), norfloxacin (NOR) and ciprofloxacin (CIP) over other Pharmaceutical and Personal Care Products (PPCPs), accomplishing the detection limit of 0.12 μmol/L, 0.52 μmol/L, 0.75 μmol/L, respectively. Notably, BUC-88 acted as an excellent fluorescence sensor for tetracyclines antibiotics with fast response time (less than 1 s), high selectivity and sensitivity (LODs = 0.08 μmol/L). The fluorescent detection method was successfully used for visual and ultrasensitive detection of ENR, NOR, CIP and tetracycline hydrochloride (TC) in lake water with satisfied recovery from 99.75% to 102.30%. Finally, the photoinduced electron transfer and the competitive absorption of ultraviolet light are the main mechanisms for sensitive detection toward quinolone antibiotics and tetracyclines antibiotics.
2022, 33(3): 1358-1364
doi: 10.1016/j.cclet.2021.09.053
Abstract:
Skeletonema costatum is a diatom widely distributed in red tide microalgae blooms and as one of the main algae causing harmful algal blooms, because of their rapid reproduction and production of toxic and harmful substances, often play a negative role in aquatic ecosystems, and human health and wellbeing. Bacillomycin D is a nonribosomal cyclic antifungal lipopeptide in the iturins family. In this study, Bacillomycin D was tested for its ability to inhibit the growth of S. costatum. The EC50 24h of Bacillomycin D on S. costatum was 24.70 μg/mL. The chlorophyll fluorescence parameters Fv/Fm, Fv/Fo, and yield of the diatoms decreased significantly with increasing concentrations of Bacillomycin D. Study of the mechanism showed that Bacillomycin D induced cell death by changing cell membrane permeability, promoting the release of cellular contents. In this study, transcriptomic analysis showed Bacillomycin D significantly inhibited the photosynthesis and metabolism of S. costatum. These findings investigated the inhibitory effect of Bacillomycin D on the growth of S. costatum and provided a theoretical foundation for the development of new environmentally friendly biological algicide.
Skeletonema costatum is a diatom widely distributed in red tide microalgae blooms and as one of the main algae causing harmful algal blooms, because of their rapid reproduction and production of toxic and harmful substances, often play a negative role in aquatic ecosystems, and human health and wellbeing. Bacillomycin D is a nonribosomal cyclic antifungal lipopeptide in the iturins family. In this study, Bacillomycin D was tested for its ability to inhibit the growth of S. costatum. The EC50 24h of Bacillomycin D on S. costatum was 24.70 μg/mL. The chlorophyll fluorescence parameters Fv/Fm, Fv/Fo, and yield of the diatoms decreased significantly with increasing concentrations of Bacillomycin D. Study of the mechanism showed that Bacillomycin D induced cell death by changing cell membrane permeability, promoting the release of cellular contents. In this study, transcriptomic analysis showed Bacillomycin D significantly inhibited the photosynthesis and metabolism of S. costatum. These findings investigated the inhibitory effect of Bacillomycin D on the growth of S. costatum and provided a theoretical foundation for the development of new environmentally friendly biological algicide.
2022, 33(3): 1365-1372
doi: 10.1016/j.cclet.2021.08.016
Abstract:
In recent years, MoS2 catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H2O2 feeding way on the whole Fenton process. Here, we report a new type of composite catalyst (MoS2-Fex) prepared in a simple way with highly dispersed iron to provide more active sites. MoS2-Fex was proved to possess selectivity for singlet oxygen (1O2) in effectively degrading sulfadiazine with a wide pH adaptability (4.0~10.0). Importantly, the mechanism of the interaction between H2O2 and MoS2 on the Fenton reaction activity was revealed through the combination of experiment and density functional theory (DFT) calculations. Compared to the traditional "a large amount for one time" feeding way of H2O2, the "small amount for multiple times" of H2O2 feeding way can increase the degradation rate of sulfadiazine from 36.9% to 91.1% in the MoS2-Fex heterogeneous Fenton system. It is demonstrated that the "small amount for multiple times" of H2O2 feeding way can reduce the side reaction of decomposition of H2O2 by MoS2 and effectively improve the utilization rate of H2O2 and the stability of MoS2-Fex. Compared with Fe2O3-based Fenton system, MoS2-Fex can significantly save the amount of H2O2. Compared with nano-iron powder, the formation of iron sludge in MoS2-Fex system was significantly reduced. Furthermore, long-term degradation test showed that the MoS2-Fe75/H2O2 system could maintain the effectiveness of degrading organic pollutants for 10 days (or even longer). This study has a guiding significance for the large-scale treatment of industrial wastewater by improved Fenton technology in the future.
In recent years, MoS2 catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H2O2 feeding way on the whole Fenton process. Here, we report a new type of composite catalyst (MoS2-Fex) prepared in a simple way with highly dispersed iron to provide more active sites. MoS2-Fex was proved to possess selectivity for singlet oxygen (1O2) in effectively degrading sulfadiazine with a wide pH adaptability (4.0~10.0). Importantly, the mechanism of the interaction between H2O2 and MoS2 on the Fenton reaction activity was revealed through the combination of experiment and density functional theory (DFT) calculations. Compared to the traditional "a large amount for one time" feeding way of H2O2, the "small amount for multiple times" of H2O2 feeding way can increase the degradation rate of sulfadiazine from 36.9% to 91.1% in the MoS2-Fex heterogeneous Fenton system. It is demonstrated that the "small amount for multiple times" of H2O2 feeding way can reduce the side reaction of decomposition of H2O2 by MoS2 and effectively improve the utilization rate of H2O2 and the stability of MoS2-Fex. Compared with Fe2O3-based Fenton system, MoS2-Fex can significantly save the amount of H2O2. Compared with nano-iron powder, the formation of iron sludge in MoS2-Fex system was significantly reduced. Furthermore, long-term degradation test showed that the MoS2-Fe75/H2O2 system could maintain the effectiveness of degrading organic pollutants for 10 days (or even longer). This study has a guiding significance for the large-scale treatment of industrial wastewater by improved Fenton technology in the future.
2022, 33(3): 1373-1376
doi: 10.1016/j.cclet.2021.08.024
Abstract:
Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale but low accuracy, incompetence in the acquirement of nano-upgraded single-cell liquid. Flow cytometry has been widely used in large-scale single-cell detection, while precise single-cell isolation relies on both a precision operating platform and a microscope, which is not only extremely inefficient, but also not conducive to couple with modern analytical instruments. Herein, we develop a modular single-cell pipette (mSCP) microfluidic chip with high efficiency and strong applicability for accurate direct capture of single viable cell from cell suspensions into nanoliter droplets (30-1000 nL). The mSCP is used as a sampling platform for the detection of CdTe quantum dots in single cells with electrothermal atomic absorption spectrometry (ETAAS) for the first time. It also ensures precise single-cell sampling and detection by inductively coupled plasma mass spectrometry (ICP-MS).
Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale but low accuracy, incompetence in the acquirement of nano-upgraded single-cell liquid. Flow cytometry has been widely used in large-scale single-cell detection, while precise single-cell isolation relies on both a precision operating platform and a microscope, which is not only extremely inefficient, but also not conducive to couple with modern analytical instruments. Herein, we develop a modular single-cell pipette (mSCP) microfluidic chip with high efficiency and strong applicability for accurate direct capture of single viable cell from cell suspensions into nanoliter droplets (30-1000 nL). The mSCP is used as a sampling platform for the detection of CdTe quantum dots in single cells with electrothermal atomic absorption spectrometry (ETAAS) for the first time. It also ensures precise single-cell sampling and detection by inductively coupled plasma mass spectrometry (ICP-MS).
2022, 33(3): 1377-1380
doi: 10.1016/j.cclet.2021.08.060
Abstract:
Membrane tension plays a significant role in many cellular processes including cell adhesion, migration and spreading. Despite the importance of membrane tension, it remains difficult to measure in vivo. Recently, the development of non-invasive fluorescent probes have made great progress, especially excited-state deplanarization in molecular rotors has been applied to image membrane tension in living cells. Nevertheless, an intrinsic limitation of such kind of probe is that they depend on the lipid packing, and how the lipid packing responds to the membrane tension change remains unclear. Therefore, in this work, we used a polarity-sensitive membrane probe to investigate the possible response mechanism of lipid packing to the change of membrane tension that was regulated by osmotic shocks. The results showed that an increase in membrane tension could stretch the lipids apart with large displacements, and this change was not homogeneous on the whole membrane, instead, increase of membrane tension induced phase separation.
Membrane tension plays a significant role in many cellular processes including cell adhesion, migration and spreading. Despite the importance of membrane tension, it remains difficult to measure in vivo. Recently, the development of non-invasive fluorescent probes have made great progress, especially excited-state deplanarization in molecular rotors has been applied to image membrane tension in living cells. Nevertheless, an intrinsic limitation of such kind of probe is that they depend on the lipid packing, and how the lipid packing responds to the membrane tension change remains unclear. Therefore, in this work, we used a polarity-sensitive membrane probe to investigate the possible response mechanism of lipid packing to the change of membrane tension that was regulated by osmotic shocks. The results showed that an increase in membrane tension could stretch the lipids apart with large displacements, and this change was not homogeneous on the whole membrane, instead, increase of membrane tension induced phase separation.
2022, 33(3): 1412-1416
doi: 10.1016/j.cclet.2021.08.025
Abstract:
Increasing active metal sites is a valid approach to improve the catalytic activity of the catalyst. Co3+ is the main active metal site of Co-based catalysts. In this research work, through the partial transformation of CoFePBA (CFP) via low-temperature heat treatment, the effective control of the Co3+/Co2+ ratio has been achieved. The partial transformation strategy of low-temperature heat treatment can not only maintain the original framework structure of CFP, but also increase more active sites. The characterization results show that the CFP-200 sample obtained via heat treatment at 200 ℃ for 2 h under N2 atmosphere has the highest Co3+/Co2+ ratio. As an oxygen evolution reaction electrocatalyst, CFP-200 shows the best electrocatalytic activity among all samples. In 1.0 mol/L KOH electrolyte, the overpotential is 312 mV at a current density of 10 mA/cm2. Therefore, low-temperature heat treatment provides an effective method for preparing low-cost and high-efficiency electrocatalysts.
Increasing active metal sites is a valid approach to improve the catalytic activity of the catalyst. Co3+ is the main active metal site of Co-based catalysts. In this research work, through the partial transformation of CoFePBA (CFP) via low-temperature heat treatment, the effective control of the Co3+/Co2+ ratio has been achieved. The partial transformation strategy of low-temperature heat treatment can not only maintain the original framework structure of CFP, but also increase more active sites. The characterization results show that the CFP-200 sample obtained via heat treatment at 200 ℃ for 2 h under N2 atmosphere has the highest Co3+/Co2+ ratio. As an oxygen evolution reaction electrocatalyst, CFP-200 shows the best electrocatalytic activity among all samples. In 1.0 mol/L KOH electrolyte, the overpotential is 312 mV at a current density of 10 mA/cm2. Therefore, low-temperature heat treatment provides an effective method for preparing low-cost and high-efficiency electrocatalysts.
2022, 33(3): 1417-1421
doi: 10.1016/j.cclet.2021.08.029
Abstract:
Molecules with multifunctional properties are of immense interest in hybrid materials, while challenges still existed because of the limited compatibility of multiple functionalities in a single system. In this work, a series of metal-organic complexes were synthesized and characterized under the assembly of electron donor phosphonate, electron acceptor polypyridine ligand and spin carrier rare earth ions. All the compounds exhibited remarkable and reversible responses with photochromism and photomodulated fluorescence, originated from photogenerated radicals via electron transfer from phosphonates to polypyridine ligands. For the Dy analog, slow magnetic relaxation was observed at cryogenic temperature, indicating the single-molecule magnetic behavior. Furthermore, photogenerated radicals could enhance the proton conductive behavior, with about 2 times larger in magnitude after light irradiation for Dy and Y compounds. The introduction of photoluminescence, magnetism and proton conduction into metallic phosphonates can provide potential applications for photochromic materials.
Molecules with multifunctional properties are of immense interest in hybrid materials, while challenges still existed because of the limited compatibility of multiple functionalities in a single system. In this work, a series of metal-organic complexes were synthesized and characterized under the assembly of electron donor phosphonate, electron acceptor polypyridine ligand and spin carrier rare earth ions. All the compounds exhibited remarkable and reversible responses with photochromism and photomodulated fluorescence, originated from photogenerated radicals via electron transfer from phosphonates to polypyridine ligands. For the Dy analog, slow magnetic relaxation was observed at cryogenic temperature, indicating the single-molecule magnetic behavior. Furthermore, photogenerated radicals could enhance the proton conductive behavior, with about 2 times larger in magnitude after light irradiation for Dy and Y compounds. The introduction of photoluminescence, magnetism and proton conduction into metallic phosphonates can provide potential applications for photochromic materials.
2022, 33(3): 1422-1424
doi: 10.1016/j.cclet.2021.08.032
Abstract:
Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O···O hydrogen bond by about 0.005 Å. This geometric isotope effect releases the internal pressure of the anionic host on the cation guests and results in a downward shift of the phase transition temperature by 10 K.
Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O···O hydrogen bond by about 0.005 Å. This geometric isotope effect releases the internal pressure of the anionic host on the cation guests and results in a downward shift of the phase transition temperature by 10 K.
2022, 33(3): 1425-1429
doi: 10.1016/j.cclet.2021.08.039
Abstract:
All-inorganic CsPbI2Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI2Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI2Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (GABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI2Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI2Br to the semitransparent solar cells.
All-inorganic CsPbI2Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI2Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI2Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (GABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI2Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI2Br to the semitransparent solar cells.
2022, 33(3): 1430-1434
doi: 10.1016/j.cclet.2021.08.058
Abstract:
In recent years, especially when there is increasing concern about the safety issue of lithium-ion batteries (LIBs), aqueous Zn-ion batteries (ZIBs) have been getting a lot of attention because of their cost-effectiveness, materials abundance, high safety, and ecological friendliness. Their working voltage and specific capacity are mainly determined by their cathode materials. Vanadium oxides are promising cathode materials for aqueous ZIBs owing to their low cost, abundant resources, and multivalence. However, vanadium oxide cathodes still suffer from unsatisfactory capacity, poor stability, and low electrical conductivity. In this work, cascading V2O3/nitrogen doped carbon (V2O3/NC) hybrid nanosheets are prepared for high-performance aqueous ZIBs by pyrolyzing pentyl viologen dibromide (PV) intercalated V2O5 nanosheets. The unique structure features of V2O3/NC nanosheets, including thin sheet-like morphology, small crystalline V2O3 nanoparticles, and conductive NC layers, endow V2O3/NC with superior performance compared to most of the reported vanadium oxide cathode materials for aqueous ZIBs. The V2O3/NC cathode exhibits the discharge capacity of 405 mAh/g at 0.5 A/g, excellent rate capability (159 mAh/g at 20 A/g), and outstanding cycling stability with 90% capacity retention over 4000 cycles at 20 A/g.
In recent years, especially when there is increasing concern about the safety issue of lithium-ion batteries (LIBs), aqueous Zn-ion batteries (ZIBs) have been getting a lot of attention because of their cost-effectiveness, materials abundance, high safety, and ecological friendliness. Their working voltage and specific capacity are mainly determined by their cathode materials. Vanadium oxides are promising cathode materials for aqueous ZIBs owing to their low cost, abundant resources, and multivalence. However, vanadium oxide cathodes still suffer from unsatisfactory capacity, poor stability, and low electrical conductivity. In this work, cascading V2O3/nitrogen doped carbon (V2O3/NC) hybrid nanosheets are prepared for high-performance aqueous ZIBs by pyrolyzing pentyl viologen dibromide (PV) intercalated V2O5 nanosheets. The unique structure features of V2O3/NC nanosheets, including thin sheet-like morphology, small crystalline V2O3 nanoparticles, and conductive NC layers, endow V2O3/NC with superior performance compared to most of the reported vanadium oxide cathode materials for aqueous ZIBs. The V2O3/NC cathode exhibits the discharge capacity of 405 mAh/g at 0.5 A/g, excellent rate capability (159 mAh/g at 20 A/g), and outstanding cycling stability with 90% capacity retention over 4000 cycles at 20 A/g.
2022, 33(3): 1435-1438
doi: 10.1016/j.cclet.2021.08.050
Abstract:
Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries (LIBs) for large-scale energy storage considering the abundance and low cost of Na-containing resources. However, the energy density of SIBs has been limited by the typically low specific capacities of traditional intercalation-based cathodes. Metal fluorides, in contrast, can deliver much higher capacities based on multi-electron conversion reactions. Among metal fluorides, CuF2 presents a theoretical specific capacity as high as 528 mAh/g while its Na-ion storage mechanism has been rarely reported. Here, we report CuF2 as a SIB cathode, which delivers a high capacity of 502 mAh/g but suffers from poor electrochemical reversibility. As a solution, we adjust the cell configuration by inserting a carbon-coated separator, which hinders the transportation of dissolved Cu ions and improves the reversibility of the CuF2 cathode. By using in-situ XRD measurements and theoretical calculation, we propose that a one-step conversion reaction occurs during the discharge process, and a reconversion reaction competes with the oxidization of Cu to dissolved Cu ion during the charge process.
Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries (LIBs) for large-scale energy storage considering the abundance and low cost of Na-containing resources. However, the energy density of SIBs has been limited by the typically low specific capacities of traditional intercalation-based cathodes. Metal fluorides, in contrast, can deliver much higher capacities based on multi-electron conversion reactions. Among metal fluorides, CuF2 presents a theoretical specific capacity as high as 528 mAh/g while its Na-ion storage mechanism has been rarely reported. Here, we report CuF2 as a SIB cathode, which delivers a high capacity of 502 mAh/g but suffers from poor electrochemical reversibility. As a solution, we adjust the cell configuration by inserting a carbon-coated separator, which hinders the transportation of dissolved Cu ions and improves the reversibility of the CuF2 cathode. By using in-situ XRD measurements and theoretical calculation, we propose that a one-step conversion reaction occurs during the discharge process, and a reconversion reaction competes with the oxidization of Cu to dissolved Cu ion during the charge process.
2022, 33(3): 1468-1474
doi: 10.1016/j.cclet.2021.08.103
Abstract:
Molybdenum disulfide (MoS2) with low cost, high activity and high earth abundance has been found to be a promising catalyst for the hydrogen evolution reaction (HER), but its catalytic activity is considerably limited due to its inert basal planes. Here, through the combination of theory and experiment, we propose that doping Ni in MoS2 as catalyst can make it have excellent catalytic activity in different reaction systems. In the EY/TEOA system, the maximum hydrogen production rate of EY/Ni-Mo-S is 2.72 times higher than that of pure EY, which confirms the strong hydrogen evolution activity of Ni-Mo-S nanosheets as catalysts. In the lactic acid and Na2S/Na2SO3 systems, when Ni-Mo-S is used as co-catalyst to compound with ZnIn2S4 (termed as Ni-Mo-S/ZnIn2S4), the maximum hydrogen evolution rates in the two systems are 5.28 and 2.33 times higher than those of pure ZnIn2S4, respectively. The difference in HER enhancement is because different systems lead to different sources of protons, thus affecting hydrogen evolution activity. Theoretically, we further demonstrate that the Ni-Mo-S nanosheets have a narrower band gap than MoS2, which is conducive to the rapid transfer of charge carriers and thus result in multi-photocatalytic reaction systems with excellent activity. The proposed atomic doping strategy provides a simple and promising approach for the design of photocatalysts with high activity and stability in multi-reaction systems.
Molybdenum disulfide (MoS2) with low cost, high activity and high earth abundance has been found to be a promising catalyst for the hydrogen evolution reaction (HER), but its catalytic activity is considerably limited due to its inert basal planes. Here, through the combination of theory and experiment, we propose that doping Ni in MoS2 as catalyst can make it have excellent catalytic activity in different reaction systems. In the EY/TEOA system, the maximum hydrogen production rate of EY/Ni-Mo-S is 2.72 times higher than that of pure EY, which confirms the strong hydrogen evolution activity of Ni-Mo-S nanosheets as catalysts. In the lactic acid and Na2S/Na2SO3 systems, when Ni-Mo-S is used as co-catalyst to compound with ZnIn2S4 (termed as Ni-Mo-S/ZnIn2S4), the maximum hydrogen evolution rates in the two systems are 5.28 and 2.33 times higher than those of pure ZnIn2S4, respectively. The difference in HER enhancement is because different systems lead to different sources of protons, thus affecting hydrogen evolution activity. Theoretically, we further demonstrate that the Ni-Mo-S nanosheets have a narrower band gap than MoS2, which is conducive to the rapid transfer of charge carriers and thus result in multi-photocatalytic reaction systems with excellent activity. The proposed atomic doping strategy provides a simple and promising approach for the design of photocatalysts with high activity and stability in multi-reaction systems.
2022, 33(3): 1475-1478
doi: 10.1016/j.cclet.2021.08.044
Abstract:
Water-soluble pillar[5]arenes are a class of typical macrocycles and have aroused tremendous attention for its easy to modify, abundant host-guest properties and extensive applications. However, up to now, all the reported water-soluble pillar[5]arenes acted as the host molecules, whereas they failed to be postsynthetically modified, which seriously impeded the development of the pillar[5]arene-based supramolecular chemistry. In this work, a new water-soluble pillar[5]arene, pillar[4]arene[1]quinone, was designed and synthsized with eight quaternary ammonium groups as well as a quinone units. Such a new water-soluble pillar[4]arene[1]quinone was capable of forming 1:1 stable complex with sodium 1-octanesulfonate in aqueous solution. Since the 1, 4-quinone unit of WP[4]Q[1] could react with ethylenediamine (EDA) to form a conjugated quinoxaline structure, so pillar[4]arene[1]quinone could apply to the facile fluorescence turn-on sensing of EDA in aqueous solution, organic solvent and air.
Water-soluble pillar[5]arenes are a class of typical macrocycles and have aroused tremendous attention for its easy to modify, abundant host-guest properties and extensive applications. However, up to now, all the reported water-soluble pillar[5]arenes acted as the host molecules, whereas they failed to be postsynthetically modified, which seriously impeded the development of the pillar[5]arene-based supramolecular chemistry. In this work, a new water-soluble pillar[5]arene, pillar[4]arene[1]quinone, was designed and synthsized with eight quaternary ammonium groups as well as a quinone units. Such a new water-soluble pillar[4]arene[1]quinone was capable of forming 1:1 stable complex with sodium 1-octanesulfonate in aqueous solution. Since the 1, 4-quinone unit of WP[4]Q[1] could react with ethylenediamine (EDA) to form a conjugated quinoxaline structure, so pillar[4]arene[1]quinone could apply to the facile fluorescence turn-on sensing of EDA in aqueous solution, organic solvent and air.
2022, 33(3): 1479-1482
doi: 10.1016/j.cclet.2021.08.036
Abstract:
A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employing 4CzIPN as the metal-free photocatalyst and dioxygen (air) as the environmentally benign oxidant. A number of sulfonated quinoxalin-2(1H)-ones were obtained in satisfactory yields with favorable functional group tolerance. Radical trapping experiment and fluorescence quenching experiments were performed to elucidate this visible-light mediated radical reaction process.
A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employing 4CzIPN as the metal-free photocatalyst and dioxygen (air) as the environmentally benign oxidant. A number of sulfonated quinoxalin-2(1H)-ones were obtained in satisfactory yields with favorable functional group tolerance. Radical trapping experiment and fluorescence quenching experiments were performed to elucidate this visible-light mediated radical reaction process.
2022, 33(3): 1483-1487
doi: 10.1016/j.cclet.2021.08.037
Abstract:
A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H4SiW12O40)-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3, 4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3, 4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.
A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H4SiW12O40)-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3, 4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3, 4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.
2022, 33(3): 1488-1492
doi: 10.1016/j.cclet.2021.08.040
Abstract:
Molecular self-assembly is the most important strategy for the development of chiral aggregates and chiral functional materials. In this study, we rationally designed and synthesized chiral fluorescent heteroclusters that were self-assembled into microscale cubosomes with a three-dimensional (3D) bicontinuous cubic phase nanostructure. The cubosomes exhibited chirality, indicating that chirality is transferred from the molecules to the 3D nanostructure. Therefore, we confirmed the formation of a chiral bicontinuous cubic phase nanostructure for the first time. We also showed that this chirality originates from the continuous change in the saddle-splay distortion of the molecules within the curved bilayer. At the same time, transparent films of chiral composites were prepared by mixing the chiral cubosomes with an epoxy resin and then curing the mixture. Therefore, we demonstrated an effective method for preparing chiral composites.
Molecular self-assembly is the most important strategy for the development of chiral aggregates and chiral functional materials. In this study, we rationally designed and synthesized chiral fluorescent heteroclusters that were self-assembled into microscale cubosomes with a three-dimensional (3D) bicontinuous cubic phase nanostructure. The cubosomes exhibited chirality, indicating that chirality is transferred from the molecules to the 3D nanostructure. Therefore, we confirmed the formation of a chiral bicontinuous cubic phase nanostructure for the first time. We also showed that this chirality originates from the continuous change in the saddle-splay distortion of the molecules within the curved bilayer. At the same time, transparent films of chiral composites were prepared by mixing the chiral cubosomes with an epoxy resin and then curing the mixture. Therefore, we demonstrated an effective method for preparing chiral composites.
2022, 33(3): 1493-1496
doi: 10.1016/j.cclet.2021.08.068
Abstract:
Because the widely used perfluorooctane sulfonate (PFOS) is harmful to both environment and human health, it is of great significance and urgency to develop sensitive and selective sensors for the detection of trace PFOS in water. In this study, a tetraphenylethylene-derived macrocycle BowtieCyclophane has been developed as a fluorescent sensor based on aggregation-induced emission enhancement and fluorochromism. Sensitive detection of PFOS has been achieved with a limit of detection (LOD) of 47.3 ± 2.0 nmol/L (25.4 ± 1.1 µg/L) accompanied by visual fluorescence color changes.
Because the widely used perfluorooctane sulfonate (PFOS) is harmful to both environment and human health, it is of great significance and urgency to develop sensitive and selective sensors for the detection of trace PFOS in water. In this study, a tetraphenylethylene-derived macrocycle BowtieCyclophane has been developed as a fluorescent sensor based on aggregation-induced emission enhancement and fluorochromism. Sensitive detection of PFOS has been achieved with a limit of detection (LOD) of 47.3 ± 2.0 nmol/L (25.4 ± 1.1 µg/L) accompanied by visual fluorescence color changes.
2022, 33(3): 1497-1500
doi: 10.1016/j.cclet.2021.08.070
Abstract:
A facile and sustainable approach for the amination of benzothiazoles with KSeCN using iodine as the catalyst in water has been disclosed under transition-metal free conditions. The reaction proceeded smoothly to afford various primary 2-amino benzothiazoles in up to 96% yield. A series of control experiments were performed, suggesting a ring-opening mechanism was involved via a radical process. This protocol provides efficient synthesis of primary 2-aminobenzothiazoles
A facile and sustainable approach for the amination of benzothiazoles with KSeCN using iodine as the catalyst in water has been disclosed under transition-metal free conditions. The reaction proceeded smoothly to afford various primary 2-amino benzothiazoles in up to 96% yield. A series of control experiments were performed, suggesting a ring-opening mechanism was involved via a radical process. This protocol provides efficient synthesis of primary 2-aminobenzothiazoles
2022, 33(3): 1501-1504
doi: 10.1016/j.cclet.2021.08.071
Abstract:
A novel and efficient electro-chemical initiated radical strategy was developed for the preparation of both N-substituted and N-unsubstituted 4-selanylisoquinolin-1(2H)-ones through selenylation of isoquinolin-1(2H)-ones with organodiselenides under chemical oxidant-, additive-free and ambient conditions.
A novel and efficient electro-chemical initiated radical strategy was developed for the preparation of both N-substituted and N-unsubstituted 4-selanylisoquinolin-1(2H)-ones through selenylation of isoquinolin-1(2H)-ones with organodiselenides under chemical oxidant-, additive-free and ambient conditions.
2022, 33(3): 1505-1510
doi: 10.1016/j.cclet.2021.08.072
Abstract:
A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a stretched form in DMSO and enhances its fluorescence after addition of a small amount of water due to aggregation-induced emission (AIE) effect. However, in the presence of a large amount of water, the TPE unit will enter the cyclodextrin cavity to form a folded self-inclusion compound. In the self-inclusion compound, not only nitrogen-containing pseudo-crown ether is formed but also arouses photo-induced electron transfer (PET) process from nitrogen atoms of triazole ring to TPE unit and quenches the fluorescence although more aggregation occurs in more water. This is the first finding that TPE-macrocycle conjugate can form pseudo-crown ether and has both the AIE phenomenon and the PET effect. Interestingly, only mercury ion arouses the fluorescence recover of the self-inclusion compound by entering the pseudo-crown ether cavity and blocking the PET process by binding to the nitrogen atoms, while other tested metal ions almost have no effect on the fluorescence. Therefore, the TPE-CD conjugate can be used for the highly selective fluorescence "Turn-On" detection of Hg2+.
A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a stretched form in DMSO and enhances its fluorescence after addition of a small amount of water due to aggregation-induced emission (AIE) effect. However, in the presence of a large amount of water, the TPE unit will enter the cyclodextrin cavity to form a folded self-inclusion compound. In the self-inclusion compound, not only nitrogen-containing pseudo-crown ether is formed but also arouses photo-induced electron transfer (PET) process from nitrogen atoms of triazole ring to TPE unit and quenches the fluorescence although more aggregation occurs in more water. This is the first finding that TPE-macrocycle conjugate can form pseudo-crown ether and has both the AIE phenomenon and the PET effect. Interestingly, only mercury ion arouses the fluorescence recover of the self-inclusion compound by entering the pseudo-crown ether cavity and blocking the PET process by binding to the nitrogen atoms, while other tested metal ions almost have no effect on the fluorescence. Therefore, the TPE-CD conjugate can be used for the highly selective fluorescence "Turn-On" detection of Hg2+.
2022, 33(3): 1511-1514
doi: 10.1016/j.cclet.2021.08.089
Abstract:
A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d5 via [4 + 1] cyclization of ClCF2COONa with non-amine compounds containing amino groups is developed. Of note, this is the first time that halofluorinated compounds are used as C1 synthon to construct deuterated nitrogen-heterocyclic compounds. The current protocol features simple operation, readily accessible raw materials, wide substrate scope and valuable products
A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d5 via [4 + 1] cyclization of ClCF2COONa with non-amine compounds containing amino groups is developed. Of note, this is the first time that halofluorinated compounds are used as C1 synthon to construct deuterated nitrogen-heterocyclic compounds. The current protocol features simple operation, readily accessible raw materials, wide substrate scope and valuable products
2022, 33(3): 1515-1518
doi: 10.1016/j.cclet.2021.08.092
Abstract:
The enantioselective epoxidation of olefin by MnⅡ(R,R-PMCP)(OTf)2, H2O2 and H2SO4 was explored by DFT calculations and experiments. Theoretical results suggest that [MnⅤ(O)(R,R-PMCP)(SO4)]+ species with a triplet ground spin state serves as the active species for the olefin epoxidation. It can be generated by the H2SO4 assisted O-O heterolysis of MnⅢ(OOH) species. MnⅢ-persulfate is also involved in this system, but it cannot promote the olefin epoxidation directly, preferring instead to transform into MnⅤ(O). Actually, the asymmetric epoxidation reactions with H2O2/H2SO4 or Oxone provide similar enantioselectivity in the presence of manganese catalyst. These observations further support the transformation of MnⅢ-persulfate to MnⅤ(O) species.
The enantioselective epoxidation of olefin by MnⅡ(R,R-PMCP)(OTf)2, H2O2 and H2SO4 was explored by DFT calculations and experiments. Theoretical results suggest that [MnⅤ(O)(R,R-PMCP)(SO4)]+ species with a triplet ground spin state serves as the active species for the olefin epoxidation. It can be generated by the H2SO4 assisted O-O heterolysis of MnⅢ(OOH) species. MnⅢ-persulfate is also involved in this system, but it cannot promote the olefin epoxidation directly, preferring instead to transform into MnⅤ(O). Actually, the asymmetric epoxidation reactions with H2O2/H2SO4 or Oxone provide similar enantioselectivity in the presence of manganese catalyst. These observations further support the transformation of MnⅢ-persulfate to MnⅤ(O) species.
2022, 33(3): 1519-1523
doi: 10.1016/j.cclet.2021.08.125
Abstract:
Lignin is the most recalcitrant of the three components of lignocellulosic biomass. The strength and stability of the linkages have long been a great challenge for the degradation and valorization of lignin biomass to obtain bio-fuels and commercial chemicals. Up to now, the selective cleavage of C–O linkages of lignin to afford chemicals contains only C, H and O atoms. Our group has developed a cleavage/cross-coupling strategy for converting 4-O-5 linkage lignin model compounds into high value-added compounds. Herein, we present a palladium-catalyzed cleavage/cross-coupling of the β-O-4 lignin model compounds with amines via dual C–O bond cleavage for the preparation of benzyl amine compounds and phenols.
Lignin is the most recalcitrant of the three components of lignocellulosic biomass. The strength and stability of the linkages have long been a great challenge for the degradation and valorization of lignin biomass to obtain bio-fuels and commercial chemicals. Up to now, the selective cleavage of C–O linkages of lignin to afford chemicals contains only C, H and O atoms. Our group has developed a cleavage/cross-coupling strategy for converting 4-O-5 linkage lignin model compounds into high value-added compounds. Herein, we present a palladium-catalyzed cleavage/cross-coupling of the β-O-4 lignin model compounds with amines via dual C–O bond cleavage for the preparation of benzyl amine compounds and phenols.
2022, 33(3): 1524-1528
doi: 10.1016/j.cclet.2021.08.106
Abstract:
Since the outer surface interaction of Q[n]s (OSIQ, including self-, anion- and aromatic-induced OSIQs) was proposed in 2014, it has become the most important research area in our group to construct various Q[n]-based supramolecular frameworks via the OSIQ strategy. Herein, we report a novel supramolecular framework constructed using cucurbit[8]uril (Q[8]) and 4-sulfocalix[6]arene (SC[6]A). This Q[8]/SC[6]A-based supramolecular framework is a product via the perfect combination of self-, anion- and aromatic-induced OSIQs. This framework has the characteristics of easy preparation and high stability with the most important feature being the sequence selective capture of specific metal cations, such as common alkali- and alkaline earth metal ions, and renewability. Thus, this framework may be used in seawater desalination, potassium ion enrichment, radioactive cesium ion pollution source treatment, Gruinard's treatment or water softening and other applications.
Since the outer surface interaction of Q[n]s (OSIQ, including self-, anion- and aromatic-induced OSIQs) was proposed in 2014, it has become the most important research area in our group to construct various Q[n]-based supramolecular frameworks via the OSIQ strategy. Herein, we report a novel supramolecular framework constructed using cucurbit[8]uril (Q[8]) and 4-sulfocalix[6]arene (SC[6]A). This Q[8]/SC[6]A-based supramolecular framework is a product via the perfect combination of self-, anion- and aromatic-induced OSIQs. This framework has the characteristics of easy preparation and high stability with the most important feature being the sequence selective capture of specific metal cations, such as common alkali- and alkaline earth metal ions, and renewability. Thus, this framework may be used in seawater desalination, potassium ion enrichment, radioactive cesium ion pollution source treatment, Gruinard's treatment or water softening and other applications.
2022, 33(3): 1529-1532
doi: 10.1016/j.cclet.2021.08.108
Abstract:
An approach for the construction of crystalline porous supramolecular organic frameworks (SOFs) via outer-surface interactions of cucurbit[6]uril (Q[6]) with high yield is presented. This approach enables the noncovalent integration of guest molecules into ordered topologies and creates new host–guest-complex-based SOFs; i.e., the topology can be predesigned and constructed by using [ZnCl4]2− anions to induce the formation of solid Q[6]-SOFs, and the pore wall surface can be easily modified by the Q[6]-encapsulated guest molecules. In addition, one of prepared solid Q[6]-SOFs showed a high drug-loading capacity and smart potential release control for drug-delivery applications
An approach for the construction of crystalline porous supramolecular organic frameworks (SOFs) via outer-surface interactions of cucurbit[6]uril (Q[6]) with high yield is presented. This approach enables the noncovalent integration of guest molecules into ordered topologies and creates new host–guest-complex-based SOFs; i.e., the topology can be predesigned and constructed by using [ZnCl4]2− anions to induce the formation of solid Q[6]-SOFs, and the pore wall surface can be easily modified by the Q[6]-encapsulated guest molecules. In addition, one of prepared solid Q[6]-SOFs showed a high drug-loading capacity and smart potential release control for drug-delivery applications
2022, 33(3): 1533-1536
doi: 10.1016/j.cclet.2021.09.001
Abstract:
The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a linear-cyclic reversible topological structure polymer based on the bistable [1]rotaxane molecular shuttle. A ferrocene-functionalized [1]rotaxane and naphthalimide fluorophore group are introduced into the both ends of the polymer, which exhibit distance-induced photo-electron transfer effect. The structural transformation between linear and cyclic state of polymer is demonstrated by simple acid-base stimuli, accompanying visual fluorescence changes. The transformation process was characterized by 1H NMR spectra and fluorescence spectra. This work provides a novel strategy to construct functionalized polymers with topological structure.
The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a linear-cyclic reversible topological structure polymer based on the bistable [1]rotaxane molecular shuttle. A ferrocene-functionalized [1]rotaxane and naphthalimide fluorophore group are introduced into the both ends of the polymer, which exhibit distance-induced photo-electron transfer effect. The structural transformation between linear and cyclic state of polymer is demonstrated by simple acid-base stimuli, accompanying visual fluorescence changes. The transformation process was characterized by 1H NMR spectra and fluorescence spectra. This work provides a novel strategy to construct functionalized polymers with topological structure.
2022, 33(3): 1537-1540
doi: 10.1016/j.cclet.2021.09.002
Abstract:
An electrochemical sensor (carboxylatopillar[5]arene-coated nitrogen-doped carbon dots, namely CCDs) based on carboxylatopillar[5]arene (CP[5]) functionalized nitrogen-doped carbon dots (N-CDs) has been developed in a facile and economic manner. To improve the performance of this electrochemical sensor in pesticide detection, the optimal solution pH (pH 7) and loading amount of CCDs on the electrode (0.50 mg/mL) have been determined. By virtue of the good conductivity of N-CDs and the molecular recognition property of CP[5], CCDs modified glassy carbon electrode, namely CCDs/GCE, shows excellent anti-interference capability, selectivity, stability, and reproducibility in the sensitive detection of paraquat. The peak currents are proportional to the paraquat concentration (from 0.1 µmol/L to 10 µmol/L) with a detection limit of 6.4 nmol/L (S/N = 3), indicating a great potential in pesticide detection. In comparison with the electrochemical sensors that require expensive metal nanoparticles and complex preparation processes, CCDs/GCE exhibits excellent detection capability of paraquat with lower cost and simpler preparation processes.
An electrochemical sensor (carboxylatopillar[5]arene-coated nitrogen-doped carbon dots, namely CCDs) based on carboxylatopillar[5]arene (CP[5]) functionalized nitrogen-doped carbon dots (N-CDs) has been developed in a facile and economic manner. To improve the performance of this electrochemical sensor in pesticide detection, the optimal solution pH (pH 7) and loading amount of CCDs on the electrode (0.50 mg/mL) have been determined. By virtue of the good conductivity of N-CDs and the molecular recognition property of CP[5], CCDs modified glassy carbon electrode, namely CCDs/GCE, shows excellent anti-interference capability, selectivity, stability, and reproducibility in the sensitive detection of paraquat. The peak currents are proportional to the paraquat concentration (from 0.1 µmol/L to 10 µmol/L) with a detection limit of 6.4 nmol/L (S/N = 3), indicating a great potential in pesticide detection. In comparison with the electrochemical sensors that require expensive metal nanoparticles and complex preparation processes, CCDs/GCE exhibits excellent detection capability of paraquat with lower cost and simpler preparation processes.
2022, 33(3): 1541-1544
doi: 10.1016/j.cclet.2021.09.004
Abstract:
Herein, we report a simple and efficient method for the direct installation of chlorodifluoroethyl group onto aromatic molecules of various aromatic amides with a new 2-chloro, 2, 2-difluoroethyl(mesityl)iodonium salt (CDFI). Moreover, the chlorodifluoroethyl compounds could be smoothly converted into difluorovinyl compounds in a one-pot or discrete procedure and regarded as a steady source of difluorovinyl compounds with "HCl-mask".
Herein, we report a simple and efficient method for the direct installation of chlorodifluoroethyl group onto aromatic molecules of various aromatic amides with a new 2-chloro, 2, 2-difluoroethyl(mesityl)iodonium salt (CDFI). Moreover, the chlorodifluoroethyl compounds could be smoothly converted into difluorovinyl compounds in a one-pot or discrete procedure and regarded as a steady source of difluorovinyl compounds with "HCl-mask".
2022, 33(3): 1545-1549
doi: 10.1016/j.cclet.2021.08.116
Abstract:
Biopolymers, including DNA and peptides have been used as excellent self-assembling building blocks for programmable single-component or hybrid materials, due to their controlled molecular interactions. However, combining two assembling principles of DNA-based programmability and peptide-based specific molecular interactions for hybrid structures to microscale has not yet been achieved. In this study, we describe a hybrid microsystem that emerges from the co-assembly of DNA origami structure and short elastin-like polypeptide conjugated oligonucleotides, and initiates liquid-liquid phase separation to generate microdroplets upon heating above the transition temperature. Moreover, the hybrid microdroplets are capable for guest molecule trapping and perform bi-/tri-enzymatic cascades with rate enhancements as open "microreactors". Our programmed assembled DNA-peptide microsystem represents a new combination of DNA nanotechnology and peptide science and opens potential application routes toward life-inspired biomaterials.
Biopolymers, including DNA and peptides have been used as excellent self-assembling building blocks for programmable single-component or hybrid materials, due to their controlled molecular interactions. However, combining two assembling principles of DNA-based programmability and peptide-based specific molecular interactions for hybrid structures to microscale has not yet been achieved. In this study, we describe a hybrid microsystem that emerges from the co-assembly of DNA origami structure and short elastin-like polypeptide conjugated oligonucleotides, and initiates liquid-liquid phase separation to generate microdroplets upon heating above the transition temperature. Moreover, the hybrid microdroplets are capable for guest molecule trapping and perform bi-/tri-enzymatic cascades with rate enhancements as open "microreactors". Our programmed assembled DNA-peptide microsystem represents a new combination of DNA nanotechnology and peptide science and opens potential application routes toward life-inspired biomaterials.
2022, 33(3): 1550-1554
doi: 10.1016/j.cclet.2021.09.008
Abstract:
1-Substituted 1, 2, 3-triazoles represents 'privileged' structural scaffolds of many clinical pharmaceuticals. However, the traditional methods for their preparation mainly rely on thermal [3 + 2] cycloaddition of potentially dangerous acetylene and azides. Here we report a base-mediated [4 + 1] annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones (DFHZ-Ts) with amines under relatively mild conditions. This azide- and acetylene-free strategy provides facile access to diverse 1-substituted 1, 2, 3-triazole derivatives in high yield in a regiospecific manner. This transformation has great functional group tolerance and can suit a broad substrate scope. Furthermore, the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality, practicability and applicability.
1-Substituted 1, 2, 3-triazoles represents 'privileged' structural scaffolds of many clinical pharmaceuticals. However, the traditional methods for their preparation mainly rely on thermal [3 + 2] cycloaddition of potentially dangerous acetylene and azides. Here we report a base-mediated [4 + 1] annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones (DFHZ-Ts) with amines under relatively mild conditions. This azide- and acetylene-free strategy provides facile access to diverse 1-substituted 1, 2, 3-triazole derivatives in high yield in a regiospecific manner. This transformation has great functional group tolerance and can suit a broad substrate scope. Furthermore, the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality, practicability and applicability.
2022, 33(3): 1555-1558
doi: 10.1016/j.cclet.2021.09.011
Abstract:
An electrochemically promoted decarboxylative borylation reaction is reported. The reaction proceeds under mild conditions in an undivided cell without use of transition metal- or photo-catalysts. The key feature of the reaction is the compatibility of diboron reagents with the electrochemical conditions. This reaction exhibits broad substrate scope, good functional group tolerability, and easy scalability.
An electrochemically promoted decarboxylative borylation reaction is reported. The reaction proceeds under mild conditions in an undivided cell without use of transition metal- or photo-catalysts. The key feature of the reaction is the compatibility of diboron reagents with the electrochemical conditions. This reaction exhibits broad substrate scope, good functional group tolerability, and easy scalability.
2022, 33(3): 1559-1562
doi: 10.1016/j.cclet.2021.09.019
Abstract:
Herein, an electrocatalytic protocol for the synthesis of 2, 3-dihydroquinazolin-4(1H)-one has been disclosed. Methanol is activated and utilized as the C1 source to cyclize with 2-aminobenzamides. This cyclization reaction proceeds conveniently (room temperature and air atmosphere) without any homogeneous metal catalysts, external oxidants, or bases. A wide variety of N, N-disubstituted 2, 3-dihydroquinazolin-4(1H)-ones are obtained via this approach. Moreover, when methanol-d4 is used, a deuterated methylene motif is incorporated into the N-heterocycles, providing an efficient approach to the deuterated N-heterocycles.
Herein, an electrocatalytic protocol for the synthesis of 2, 3-dihydroquinazolin-4(1H)-one has been disclosed. Methanol is activated and utilized as the C1 source to cyclize with 2-aminobenzamides. This cyclization reaction proceeds conveniently (room temperature and air atmosphere) without any homogeneous metal catalysts, external oxidants, or bases. A wide variety of N, N-disubstituted 2, 3-dihydroquinazolin-4(1H)-ones are obtained via this approach. Moreover, when methanol-d4 is used, a deuterated methylene motif is incorporated into the N-heterocycles, providing an efficient approach to the deuterated N-heterocycles.
2022, 33(3): 1563-1566
doi: 10.1016/j.cclet.2021.09.028
Abstract:
N6-methyl adenosine (m6A) is an eminent epigenetic mark in mRNAs that affects a broad range of biological functions in diverse species. However, the chemically inert methyl group prevents a direct labeling of this modification for subsequent detection and sequencing. Therefore, most current approaches for the labeling of m6A still have limitations of relying on the utilization of corresponding methyltransferases, which resulted in the lacking of efficiency. Here we present an approach which selectively alkylated the N6-formyl adenosine (f6A), the key intermediate during chemical oxidation of m6A, with an alkyne functionality that can be further labeled with click reactions. This covalent labeling approach will be able to facilitate in the affinity purification, detection and genome-wide profiling studies.
N6-methyl adenosine (m6A) is an eminent epigenetic mark in mRNAs that affects a broad range of biological functions in diverse species. However, the chemically inert methyl group prevents a direct labeling of this modification for subsequent detection and sequencing. Therefore, most current approaches for the labeling of m6A still have limitations of relying on the utilization of corresponding methyltransferases, which resulted in the lacking of efficiency. Here we present an approach which selectively alkylated the N6-formyl adenosine (f6A), the key intermediate during chemical oxidation of m6A, with an alkyne functionality that can be further labeled with click reactions. This covalent labeling approach will be able to facilitate in the affinity purification, detection and genome-wide profiling studies.
2022, 33(3): 1567-1571
doi: 10.1016/j.cclet.2021.08.111
Abstract:
The therapy of non-small lung cancer (NSCLC) is limited by wide metastasis and chemotherapy resistance, herein, we present a new cancer-targeting prodrug PBG with the integration of real-time fluorescence visualization. The potent anticancer drug Gefitinib conjugates a biotin recognition ligand yielding the prodrug PBG via a GSH-activatable disulfide bond linker. Once coupling a near-infrared azo-BODIPY fluorophore into the molecular structure of PBG, we obtain its fluorescent theranostic TBG. The prodrug PBG can sustain Gefitinib release by the high level of GSH in the pathophysiological milieu. We evaluate the drug delivery of the prodrug PBG using fluorescent TBG in PC9 cancer bearing nude mice models, which indicate that TBG can be utilized to monitor the in vivo drug release process. Prodrug PBG can be targeted to accumulate in the cancer lesion with a better and efficaciously therapeutic result compared with the single Gefitinib treatment in cells and in vivo. The fluorescence images also reveal that the targeting accumulation and longitudinal retention of anticancer drug in cancer lesions will contribute to the superior therapeutic effects. The above applications of our new prodrug PBG and its fluorescent theranostic TBG have the potential contribution to the research in biology and the clinical medicine.
The therapy of non-small lung cancer (NSCLC) is limited by wide metastasis and chemotherapy resistance, herein, we present a new cancer-targeting prodrug PBG with the integration of real-time fluorescence visualization. The potent anticancer drug Gefitinib conjugates a biotin recognition ligand yielding the prodrug PBG via a GSH-activatable disulfide bond linker. Once coupling a near-infrared azo-BODIPY fluorophore into the molecular structure of PBG, we obtain its fluorescent theranostic TBG. The prodrug PBG can sustain Gefitinib release by the high level of GSH in the pathophysiological milieu. We evaluate the drug delivery of the prodrug PBG using fluorescent TBG in PC9 cancer bearing nude mice models, which indicate that TBG can be utilized to monitor the in vivo drug release process. Prodrug PBG can be targeted to accumulate in the cancer lesion with a better and efficaciously therapeutic result compared with the single Gefitinib treatment in cells and in vivo. The fluorescence images also reveal that the targeting accumulation and longitudinal retention of anticancer drug in cancer lesions will contribute to the superior therapeutic effects. The above applications of our new prodrug PBG and its fluorescent theranostic TBG have the potential contribution to the research in biology and the clinical medicine.
2022, 33(3): 1572-1576
doi: 10.1016/j.cclet.2021.08.114
Abstract:
Monoamine oxidase A (MAO-A) is a prominent myocardial source of reactive oxygen species (ROS), and its expression and activity are strongly increased in failing hearts. Therefore, accurate evaluation of MAO-A activity in cardiomyocytes is of great importance for understanding its biological functions and early diagnosing the progression of heart failure. However, so far, there is no report on the fluorescent diagnosis of heart failure by a specific probe for MAO-A. In this work, two far-red emissive fluorescent turn-on probes (KXS-M1 and KXS-M2) for the highly selective and sensitive detection of MAO-A were fabricated. Both probes exhibit good response to MAO-A, one of which, KXS-M2, performs better than the other one in terms of a fluorescence increment and sensitivity. Using the pioneering probe KXS-M2, specific fluorescence imaging of MAO-A in glucose-deprived H9c2 cardiac cells, zebrafish and isoprenaline-induced failing heart tissues was achieved, proving that KXS-M2 can serve as a powerful tool for the diagnosis and treatment of heart failure.
Monoamine oxidase A (MAO-A) is a prominent myocardial source of reactive oxygen species (ROS), and its expression and activity are strongly increased in failing hearts. Therefore, accurate evaluation of MAO-A activity in cardiomyocytes is of great importance for understanding its biological functions and early diagnosing the progression of heart failure. However, so far, there is no report on the fluorescent diagnosis of heart failure by a specific probe for MAO-A. In this work, two far-red emissive fluorescent turn-on probes (KXS-M1 and KXS-M2) for the highly selective and sensitive detection of MAO-A were fabricated. Both probes exhibit good response to MAO-A, one of which, KXS-M2, performs better than the other one in terms of a fluorescence increment and sensitivity. Using the pioneering probe KXS-M2, specific fluorescence imaging of MAO-A in glucose-deprived H9c2 cardiac cells, zebrafish and isoprenaline-induced failing heart tissues was achieved, proving that KXS-M2 can serve as a powerful tool for the diagnosis and treatment of heart failure.
A "cluster bomb" oral drug delivery system to sequentially overcome the multiple absorption barriers
2022, 33(3): 1577-1583
doi: 10.1016/j.cclet.2021.08.113
Abstract:
Oral drugs have been widely used in clinical therapy, but their developments were severely limited by the side effects of drug exposure as well as the multiple biological barriers. In this study, we constructed a "cluster bomb" oral drug delivery system (DOX@PFeL@L100) with core-shell structure to overcome the complex absorption barriers. The inner core termed as "bomb" that contains a lot of ultra-small diameter Fe3O4 nanoparticles (DOX@PFeL NPs) loaded with doxorubicin (DOX) and modified with l-valine, which can efficiently penetrate the epithelial cells via PePT1 receptor mediated endocytosis. The outer shell of this "cluster bomb" is a layer of pH-sensitive polymer (Eudragit®L100) that can be served as a pH-responsive switch and effectively control the "bomb" release in the intestinal microenvironment to improve the antitumor efficiency by the Fenton like reaction of DOX and Fe2+/Fe3+. This study demonstrates that the "cluster comb" oral drug delivery system can sequentially overcome the multiple biological barriers, providing a safe and effective approach for tumor therapy.
Oral drugs have been widely used in clinical therapy, but their developments were severely limited by the side effects of drug exposure as well as the multiple biological barriers. In this study, we constructed a "cluster bomb" oral drug delivery system (DOX@PFeL@L100) with core-shell structure to overcome the complex absorption barriers. The inner core termed as "bomb" that contains a lot of ultra-small diameter Fe3O4 nanoparticles (DOX@PFeL NPs) loaded with doxorubicin (DOX) and modified with l-valine, which can efficiently penetrate the epithelial cells via PePT1 receptor mediated endocytosis. The outer shell of this "cluster bomb" is a layer of pH-sensitive polymer (Eudragit®L100) that can be served as a pH-responsive switch and effectively control the "bomb" release in the intestinal microenvironment to improve the antitumor efficiency by the Fenton like reaction of DOX and Fe2+/Fe3+. This study demonstrates that the "cluster comb" oral drug delivery system can sequentially overcome the multiple biological barriers, providing a safe and effective approach for tumor therapy.
2022, 33(3): 1584-1588
doi: 10.1016/j.cclet.2021.09.046
Abstract:
Pyrazinamide (PZA), isoniazid (INH) and rifampicin (RFP) are all commonly used anti-tuberculosis drugs in clinical practice, and long-term medication may cause severe liver damage and toxicity. The level of peroxynitrite (ONOO–) generated in liver has long been regarded as a biomarker for the prediction and measurement of drug-induced liver injury (DILI). In this article, we constructed a BODIPY-based fluorescent probe (BDP-Py+) that enabled quickly and sensitively detect and image ONOO– in vivo. Utilizing this probe, we demonstrated the change of ONOO– content in cells and mice model of DILI induced by acetaminophen (APAP), and for the first time revealed the mechanism of liver injury induced by antituberculosis drug PZA. Moreover, BDP-Py+ could be applied to screen out and evaluate the hepatotoxicity of different anti-tuberculosis drugs. Comparing with the existing serum enzymes detection and H & E staining, the probe could achieve early diagnosis of DILI before solid lesions in liver via monitoring the up-regulation of ONOO– levels. Collectively, this work will promote the understanding of the pathogenesis of anti-tuberculosis drug induced liver injury (ATB-DILI), and provide a powerful tool for the early diagnosis and treatment of DILI.
Pyrazinamide (PZA), isoniazid (INH) and rifampicin (RFP) are all commonly used anti-tuberculosis drugs in clinical practice, and long-term medication may cause severe liver damage and toxicity. The level of peroxynitrite (ONOO–) generated in liver has long been regarded as a biomarker for the prediction and measurement of drug-induced liver injury (DILI). In this article, we constructed a BODIPY-based fluorescent probe (BDP-Py+) that enabled quickly and sensitively detect and image ONOO– in vivo. Utilizing this probe, we demonstrated the change of ONOO– content in cells and mice model of DILI induced by acetaminophen (APAP), and for the first time revealed the mechanism of liver injury induced by antituberculosis drug PZA. Moreover, BDP-Py+ could be applied to screen out and evaluate the hepatotoxicity of different anti-tuberculosis drugs. Comparing with the existing serum enzymes detection and H & E staining, the probe could achieve early diagnosis of DILI before solid lesions in liver via monitoring the up-regulation of ONOO– levels. Collectively, this work will promote the understanding of the pathogenesis of anti-tuberculosis drug induced liver injury (ATB-DILI), and provide a powerful tool for the early diagnosis and treatment of DILI.
2022, 33(3): 1589-1594
doi: 10.1016/j.cclet.2021.09.013
Abstract:
Hypoxia is one of the key characteristics of solid tumors. The over-expression of azoreductase resulting from hypoxia can be used as a target to visualize hypoxic levels and a trigger of the drug release system in tumor treatment. In this work, we developed a near-infrared fluorescent probe YLOD, composed of a near-infrared fluorophore, an azo bond, and an analogue of the anti-tumor drug melphalan. In the presence of azoreductase, YLOD displayed a red emission at 620 nm and released the anti-tumor drug concomitantly, thus achieving the integrated effects of hypoxic imaging and tumor treatment. Furthermore, YLOD successfully inhibited the growth of solid tumors during the tumor suppression experiments in nude mice. Considering all the results, YLOD emerges as a new fluorescence tool that can quickly determine the location and the edges of a tumor, showing concrete potential in clinical cancer treatment.
Hypoxia is one of the key characteristics of solid tumors. The over-expression of azoreductase resulting from hypoxia can be used as a target to visualize hypoxic levels and a trigger of the drug release system in tumor treatment. In this work, we developed a near-infrared fluorescent probe YLOD, composed of a near-infrared fluorophore, an azo bond, and an analogue of the anti-tumor drug melphalan. In the presence of azoreductase, YLOD displayed a red emission at 620 nm and released the anti-tumor drug concomitantly, thus achieving the integrated effects of hypoxic imaging and tumor treatment. Furthermore, YLOD successfully inhibited the growth of solid tumors during the tumor suppression experiments in nude mice. Considering all the results, YLOD emerges as a new fluorescence tool that can quickly determine the location and the edges of a tumor, showing concrete potential in clinical cancer treatment.
2022, 33(3): 1595-1598
doi: 10.1016/j.cclet.2021.09.016
Abstract:
Substrate photopatterning has provided versatile applications in biomedical fields. Herein, an universal and efficient photoligation reaction has been used to prepare a patterned capture substrate for a sandwich SERS immunoassay. Photoirradiation induces mild and efficient immobilization of antibodies at the desired region of a gold surface, and the antibody-antigen interaction helps the substrate to capture the antigens in solution specifically. After exposing to SERS probes, i.e., the gold nanoparticles labelled with both antibodies and intrinsically strong Raman reporters, multiple quantitative SERS determination of antigens can be achieved with high sensitivity and specificity. The limit of detection can be as low as 10−12 mol/L for four kinds of cancer biomarkers, which provides a promising method for the construction of highly sensitive and high-throughput SERS detection chip and the application of in vitro diagnosis.
Substrate photopatterning has provided versatile applications in biomedical fields. Herein, an universal and efficient photoligation reaction has been used to prepare a patterned capture substrate for a sandwich SERS immunoassay. Photoirradiation induces mild and efficient immobilization of antibodies at the desired region of a gold surface, and the antibody-antigen interaction helps the substrate to capture the antigens in solution specifically. After exposing to SERS probes, i.e., the gold nanoparticles labelled with both antibodies and intrinsically strong Raman reporters, multiple quantitative SERS determination of antigens can be achieved with high sensitivity and specificity. The limit of detection can be as low as 10−12 mol/L for four kinds of cancer biomarkers, which provides a promising method for the construction of highly sensitive and high-throughput SERS detection chip and the application of in vitro diagnosis.
2022, 33(3): 1599-1603
doi: 10.1016/j.cclet.2021.09.018
Abstract:
Fast skin repair is critical for less infection, less pain and high quality of life, which is still limited with undesirable rehabilitation speed and side effects. Currently, laser-activated silk sealant agent without suture and gauze has been demonstrated promising for fast skin repair taking advantage of its structural transformation after heating. Nevertheless, more efficient healing effects and less side effects of laser-activated silk sealant agent remains challenging due to absence of suitable photo-thermal materials and robust/biomimetic protein materials. In this work, the marriage between silk protein and Rehmanniae radix preparata (a kind of the traditional Chinese herb) has been demonstrated as a novel and effective way to achieve an excellent healing effect for skin repair. The non-toxicity, high photothermal conversion efficiency and healing mechanism are systematically studied and proved. This new methodology might shed a new light for combining dark traditional Chinese medicine and silk fibroin for advanced wound healing technology.
Fast skin repair is critical for less infection, less pain and high quality of life, which is still limited with undesirable rehabilitation speed and side effects. Currently, laser-activated silk sealant agent without suture and gauze has been demonstrated promising for fast skin repair taking advantage of its structural transformation after heating. Nevertheless, more efficient healing effects and less side effects of laser-activated silk sealant agent remains challenging due to absence of suitable photo-thermal materials and robust/biomimetic protein materials. In this work, the marriage between silk protein and Rehmanniae radix preparata (a kind of the traditional Chinese herb) has been demonstrated as a novel and effective way to achieve an excellent healing effect for skin repair. The non-toxicity, high photothermal conversion efficiency and healing mechanism are systematically studied and proved. This new methodology might shed a new light for combining dark traditional Chinese medicine and silk fibroin for advanced wound healing technology.
2022, 33(3): 1604-1608
doi: 10.1016/j.cclet.2021.09.084
Abstract:
Thermotherapy and chemotherapy have received extensive attention to tumor treatment. However, thermal tolerance and drug resistance severely limit clinical effect of tumor therapy owing to endoplasmic reticulum (ER) stress. Reducing thermal tolerance and drug resistance of tumors is an urgent challenge to be solved. In this work, we design a nanoplatform of PBA-Dtxl@MIL-101 as an ER inhibitor. Amino functionalized Fe-metal organic framework (MIL-101) nanoparticles are synthesized as pH and microwave (MW) dual stimuli-responsive drug delivery system. Then, the chemical chaperones of 4-phenylbutyric acid (PBA) and antineoplastic drug Docetaxel (Dtxl) were successfully loaded into MIL-101 nanoparticles to form PBA-Dtxl@MIL-101 nanoparticles. Furthermore, PBA-Dtxl@MIL-101 nanoparticles exhibit inhibitor effect of ER stress through upregulating caspase 9 proteins and reduce thermal tolerance by downregulating HSP 90. It was demonstrated that the therapy sensitized by PBA-Dtxl@MIL-101 nanoparticles obviously destroyed tumor cells, showing simultaneously enhanced thermo-chemo therapy.
Thermotherapy and chemotherapy have received extensive attention to tumor treatment. However, thermal tolerance and drug resistance severely limit clinical effect of tumor therapy owing to endoplasmic reticulum (ER) stress. Reducing thermal tolerance and drug resistance of tumors is an urgent challenge to be solved. In this work, we design a nanoplatform of PBA-Dtxl@MIL-101 as an ER inhibitor. Amino functionalized Fe-metal organic framework (MIL-101) nanoparticles are synthesized as pH and microwave (MW) dual stimuli-responsive drug delivery system. Then, the chemical chaperones of 4-phenylbutyric acid (PBA) and antineoplastic drug Docetaxel (Dtxl) were successfully loaded into MIL-101 nanoparticles to form PBA-Dtxl@MIL-101 nanoparticles. Furthermore, PBA-Dtxl@MIL-101 nanoparticles exhibit inhibitor effect of ER stress through upregulating caspase 9 proteins and reduce thermal tolerance by downregulating HSP 90. It was demonstrated that the therapy sensitized by PBA-Dtxl@MIL-101 nanoparticles obviously destroyed tumor cells, showing simultaneously enhanced thermo-chemo therapy.
2022, 33(3): 1609-1612
doi: 10.1016/j.cclet.2021.09.036
Abstract:
Homocysteine (Hcy), cysteine (Cys) and glutathione (GSH) play crucial roles in redox homeostasis during mitochondria functions. Simultaneous differentiation and visualization of mitochondrial biothiols dynamics are significant for understanding cell metabolism and their related diseases. Herein, a multisite-binding fluorescent probe (MCP) was developed for simultaneous sensing of mitochondrial Cys, GSH and Hcy from three fluorescence channels for the first time. This novel probe exhibited rapid fluorescence turn-on, good water-solubility, high selectivity and large spectral separation for discriminating Cys, GSH and Hcy with 131-, 96-, 748-fold fluorescence increasement at 471, 520, 567 nm through different excitation wavelengths, respectively. Importantly, this probe was successfully applied to simultaneous monitoring of mitochondrial Cys, GSH, and Hcy in live cells and zebrafish from three fluorescence channels, promoting the understanding of the functions of Hcy, Cys and GSH.
Homocysteine (Hcy), cysteine (Cys) and glutathione (GSH) play crucial roles in redox homeostasis during mitochondria functions. Simultaneous differentiation and visualization of mitochondrial biothiols dynamics are significant for understanding cell metabolism and their related diseases. Herein, a multisite-binding fluorescent probe (MCP) was developed for simultaneous sensing of mitochondrial Cys, GSH and Hcy from three fluorescence channels for the first time. This novel probe exhibited rapid fluorescence turn-on, good water-solubility, high selectivity and large spectral separation for discriminating Cys, GSH and Hcy with 131-, 96-, 748-fold fluorescence increasement at 471, 520, 567 nm through different excitation wavelengths, respectively. Importantly, this probe was successfully applied to simultaneous monitoring of mitochondrial Cys, GSH, and Hcy in live cells and zebrafish from three fluorescence channels, promoting the understanding of the functions of Hcy, Cys and GSH.
2022, 33(3): 1613-1618
doi: 10.1016/j.cclet.2021.09.048
Abstract:
It has been challenging to achieve multi-photochromic systems without affecting the individual photoswitching properties of the constituent units. Herein, we present the design and synthesis of a new family of platinum-acetylide dendrimers containing up to twenty-one photochromic dithienylethene (DTE) units that exhibit both high photochromic efficiency and individual switching properties. Upon irradiation with ultraviolet (UV) and visible (vis) light, the resultant metallodendrimers display high conversion yield and good fatigue resistance. More interestingly, cyclization-cycloreversion kinetics revealed that the photochromic property of each DTE unit in these metallodendrimers is unaffected by its neighbor and the full ring-closure of up to twenty-one DTE units in one single dendrimer has been achieved.
It has been challenging to achieve multi-photochromic systems without affecting the individual photoswitching properties of the constituent units. Herein, we present the design and synthesis of a new family of platinum-acetylide dendrimers containing up to twenty-one photochromic dithienylethene (DTE) units that exhibit both high photochromic efficiency and individual switching properties. Upon irradiation with ultraviolet (UV) and visible (vis) light, the resultant metallodendrimers display high conversion yield and good fatigue resistance. More interestingly, cyclization-cycloreversion kinetics revealed that the photochromic property of each DTE unit in these metallodendrimers is unaffected by its neighbor and the full ring-closure of up to twenty-one DTE units in one single dendrimer has been achieved.
2022, 33(3): 1619-1622
doi: 10.1016/j.cclet.2021.09.045
Abstract:
Infectious diseases become one of the leading causes of human death. Traditional treatment based on classical antibiotics could not provide enough antibacterial activity to combat bacterial infections due to low bioavailability, even leading to antibiotic resistance. In recent years, biomimetic delivery systems have been developed to improve drug therapy for various diseases, such as malignant tumor and cardiovascular disease. In this work, we designed virus-inspired nanodrugs (VNDs) through co-assembly of amphiphilic lipopeptide dendrons and poly(lactic-co-glycolic acid) polymers for high-efficiency antibiotic delivery. These VNDs had well-defined and stable nanostructures for tetracycline encapsulation and delivery. The VNDs were capable of promoting antibiotic internalization and enhancing their antibacterial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Additionally, no obvious cytotoxicity of VNDs was observed to human cell lines. This work successfully demonstrated the virus-mimetic nanoparticles served as promising and applicable antibiotic delivery platform for antibacterial treatment.
Infectious diseases become one of the leading causes of human death. Traditional treatment based on classical antibiotics could not provide enough antibacterial activity to combat bacterial infections due to low bioavailability, even leading to antibiotic resistance. In recent years, biomimetic delivery systems have been developed to improve drug therapy for various diseases, such as malignant tumor and cardiovascular disease. In this work, we designed virus-inspired nanodrugs (VNDs) through co-assembly of amphiphilic lipopeptide dendrons and poly(lactic-co-glycolic acid) polymers for high-efficiency antibiotic delivery. These VNDs had well-defined and stable nanostructures for tetracycline encapsulation and delivery. The VNDs were capable of promoting antibiotic internalization and enhancing their antibacterial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Additionally, no obvious cytotoxicity of VNDs was observed to human cell lines. This work successfully demonstrated the virus-mimetic nanoparticles served as promising and applicable antibiotic delivery platform for antibacterial treatment.
2022, 33(3): 1623-1626
doi: 10.1016/j.cclet.2021.09.105
Abstract:
Treatment of bone defects still poses a great challenge in orthopedic clinics, and the vital role of periosteum in such processes has attracted widespread attention. However, studies focusing on the oxidative stress micro-environment with an artificial periosteum at the site of defect have been scarce. The intrinsic anti-oxidative properties and therapeutic potential for bone defects of metal-phenolic networks (MPNs) have provided a potential solution to this. Herein, we have developed a protocatechualdehyde + zinc ion (PCA+ZnⅡ) MPN coating on a thermoplastic polyurethane membrane with a one-pot method to fabricate a new-type of periosteum with meritorious biocompatibility and abilities of modulating oxidative stress condition and promoting osteogenesis and mineralization for better bone regeneration, which has shown to be a promising strategy for constructing artificial periosteum with various MPNs.
Treatment of bone defects still poses a great challenge in orthopedic clinics, and the vital role of periosteum in such processes has attracted widespread attention. However, studies focusing on the oxidative stress micro-environment with an artificial periosteum at the site of defect have been scarce. The intrinsic anti-oxidative properties and therapeutic potential for bone defects of metal-phenolic networks (MPNs) have provided a potential solution to this. Herein, we have developed a protocatechualdehyde + zinc ion (PCA+ZnⅡ) MPN coating on a thermoplastic polyurethane membrane with a one-pot method to fabricate a new-type of periosteum with meritorious biocompatibility and abilities of modulating oxidative stress condition and promoting osteogenesis and mineralization for better bone regeneration, which has shown to be a promising strategy for constructing artificial periosteum with various MPNs.
2022, 33(3): 1627-1631
doi: 10.1016/j.cclet.2021.09.087
Abstract:
Several probes containing benzothiazole-guided conjugated systems (BGCS) were designed and synthesized, and two molecules (BGCS5 and BGCS6) of which were discovered as selective probes targeting c-MYC Pu22 G-quadruplex DNA. The fluorescence intensity of BGCS5 and BGCS6 in the presence of c-MYC Pu22 far exceeds that of the typical G4 probe TO1. Especially, the fluorescence of BGCS6 increased almost 193-fold in the presence of c-MYC Pu22 G4 compared to that alone in aqueous buffer condition with almost no fluorescence and 10–30 folds than those in the presence of other DNAs, which will be useful tools for disease detection in mammals.
Several probes containing benzothiazole-guided conjugated systems (BGCS) were designed and synthesized, and two molecules (BGCS5 and BGCS6) of which were discovered as selective probes targeting c-MYC Pu22 G-quadruplex DNA. The fluorescence intensity of BGCS5 and BGCS6 in the presence of c-MYC Pu22 far exceeds that of the typical G4 probe TO1. Especially, the fluorescence of BGCS6 increased almost 193-fold in the presence of c-MYC Pu22 G4 compared to that alone in aqueous buffer condition with almost no fluorescence and 10–30 folds than those in the presence of other DNAs, which will be useful tools for disease detection in mammals.
2022, 33(3): 1632-1636
doi: 10.1016/j.cclet.2021.09.086
Abstract:
Benzoyl peroxide (BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot (CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response. Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.
Benzoyl peroxide (BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot (CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response. Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.
2022, 33(3): 1637-1642
doi: 10.1016/j.cclet.2021.09.088
Abstract:
Imaging dynamics of membrane proteins of live cells in a wash-free and real-time manner has been a challenging task. Herein, we report unprecedented applications of malachite green (MG), an organic dye widely used in pigment industry, as a switchable fluorophore to monitor membrane enzymes or non-catalytic proteins in live cells. Conformationally flexible MG is non-fluorescent in aqueous solution, yet covalent binding with endogenous proteins of cells significantly enhances its fluorescence at 670 nm by restricting flexibility of dye. Integrating a phosphate-caged quinone methide precursor with MG yielded a covalent labeling fluorogenic probe, allowing real-time imaging of membrane alkaline phosphatase (ALP, a model catalytic protein) activity in live cells with over 100-fold enhancement of fluorescence intensity. Moreover, MG is also applicable to image non-catalytic protein by conjugation with protein-specific ligand. A fluorogenic probe consisted of c-RGDfK peptide and MG proved to be compatible with wash-free and real-time visualization of non-catalytic integrin αvβ3 in live cells with high contrast.
Imaging dynamics of membrane proteins of live cells in a wash-free and real-time manner has been a challenging task. Herein, we report unprecedented applications of malachite green (MG), an organic dye widely used in pigment industry, as a switchable fluorophore to monitor membrane enzymes or non-catalytic proteins in live cells. Conformationally flexible MG is non-fluorescent in aqueous solution, yet covalent binding with endogenous proteins of cells significantly enhances its fluorescence at 670 nm by restricting flexibility of dye. Integrating a phosphate-caged quinone methide precursor with MG yielded a covalent labeling fluorogenic probe, allowing real-time imaging of membrane alkaline phosphatase (ALP, a model catalytic protein) activity in live cells with over 100-fold enhancement of fluorescence intensity. Moreover, MG is also applicable to image non-catalytic protein by conjugation with protein-specific ligand. A fluorogenic probe consisted of c-RGDfK peptide and MG proved to be compatible with wash-free and real-time visualization of non-catalytic integrin αvβ3 in live cells with high contrast.
2022, 33(3): 1643-1646
doi: 10.1016/j.cclet.2021.08.026
Abstract:
Three novel series of α-aminoamides derivatives were designed and synthesized based on ralfinamide, and their Nav1.7 inhibitory activities were evaluated using manual patch clamp electrophysiology. Active compounds inhibited Nav1.7 with half maximal inhibitory concentration (IC50) values ranging from 2.9 µmol/L to 21.4 µmol/L. Among them, the most potent compound 19h exhibited about 12-fold potency better than ralfinamide. The investigation of their structure-activity relationship gives a strategy to improve the Nav1.7 inhibition of ralfinamide analogues. Compound 19h was efficacious in antinociception in the mouse spared nerve injury (SNI) model of neuropathic pain without causing sedation in the open field test.
Three novel series of α-aminoamides derivatives were designed and synthesized based on ralfinamide, and their Nav1.7 inhibitory activities were evaluated using manual patch clamp electrophysiology. Active compounds inhibited Nav1.7 with half maximal inhibitory concentration (IC50) values ranging from 2.9 µmol/L to 21.4 µmol/L. Among them, the most potent compound 19h exhibited about 12-fold potency better than ralfinamide. The investigation of their structure-activity relationship gives a strategy to improve the Nav1.7 inhibition of ralfinamide analogues. Compound 19h was efficacious in antinociception in the mouse spared nerve injury (SNI) model of neuropathic pain without causing sedation in the open field test.
