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2018 Volume 29 Issue 11
2018, 29(11): 1545-1559
doi: 10.1016/j.cclet.2018.09.005
Abstract:
Optical sensors are widely used in the field of analytical sensing and optical imaging because of their high sensitivity, fast response time, and technical simplicity. The advantages of sensors lay in their noninvasive approach within biological tissues and inherent reliability in fluorescence imaging tests. In recent years the development of optical sensors for the sensing of ions, neutral molecules and especially tumor micro-environment-related parameters has been an active research area. This review focuses on recent contributions concerning fluorescent or colorimetric sensors and is organized according to their target classifications.
Optical sensors are widely used in the field of analytical sensing and optical imaging because of their high sensitivity, fast response time, and technical simplicity. The advantages of sensors lay in their noninvasive approach within biological tissues and inherent reliability in fluorescence imaging tests. In recent years the development of optical sensors for the sensing of ions, neutral molecules and especially tumor micro-environment-related parameters has been an active research area. This review focuses on recent contributions concerning fluorescent or colorimetric sensors and is organized according to their target classifications.
2018, 29(11): 1560-1566
doi: 10.1016/j.cclet.2018.01.032
Abstract:
Cucurbit[n]urils (CB[n]s, n=5-8, 10, 13-15) have been proven to be an interesting macrocyclic family with their distinctive molecular recognition properties and fascinating applications in fields such as catalysis, supramolecular materials, drug delivery and biological systems. With the biggest cavity in the CB[n]s family, CB[10] shows its unique molecular recognition properties that are rather distinctive from other CB[n]s. In this review, we summarize the progresses in CB[10]-based chemistry since CB[10] was first reported as CB[10]·CB[5] complex in 2001. Purification, molecular recognition and supramolecular assembly of CB[10] will be described and an outlook will be given for further exploration of CB[10]-based chemistry.
Cucurbit[n]urils (CB[n]s, n=5-8, 10, 13-15) have been proven to be an interesting macrocyclic family with their distinctive molecular recognition properties and fascinating applications in fields such as catalysis, supramolecular materials, drug delivery and biological systems. With the biggest cavity in the CB[n]s family, CB[10] shows its unique molecular recognition properties that are rather distinctive from other CB[n]s. In this review, we summarize the progresses in CB[10]-based chemistry since CB[10] was first reported as CB[10]·CB[5] complex in 2001. Purification, molecular recognition and supramolecular assembly of CB[10] will be described and an outlook will be given for further exploration of CB[10]-based chemistry.
2018, 29(11): 1567-1577
doi: 10.1016/j.cclet.2017.12.008
Abstract:
Recently, lateral flow assay (LFA) has attracted researchers' attention because of its considerable advantages of superior portability, rapid detection, cost-effectiveness and ease of use. This review provides a brief overview of latest researches of LFA, including the practical use of LFA in both qualitative and quantitative analysis in different areas. Though bio-recognition molecules in the LFA used to be antibodies, a new kind of recognition element called aptamer, showing significant advantages, is developed rapidly in recent years. The highly specific recognition of aptamers/antibodies and targets are combined with the excellent properties of a dry-reagent strip biosensor that enables efficiently detection in point-of-care applications. Herein, we compared the aptamers with antibodies, summarized the principle of LFAs, and three main elements for the LFAs (recognition molecule, signal transduction element, the targets). Additionally, we summarized different optimal experimental conditions in the recent LFA-related studies to give detailed overview of the LFA development. We hope the review can give a general guide for the development of LFAs.
Recently, lateral flow assay (LFA) has attracted researchers' attention because of its considerable advantages of superior portability, rapid detection, cost-effectiveness and ease of use. This review provides a brief overview of latest researches of LFA, including the practical use of LFA in both qualitative and quantitative analysis in different areas. Though bio-recognition molecules in the LFA used to be antibodies, a new kind of recognition element called aptamer, showing significant advantages, is developed rapidly in recent years. The highly specific recognition of aptamers/antibodies and targets are combined with the excellent properties of a dry-reagent strip biosensor that enables efficiently detection in point-of-care applications. Herein, we compared the aptamers with antibodies, summarized the principle of LFAs, and three main elements for the LFAs (recognition molecule, signal transduction element, the targets). Additionally, we summarized different optimal experimental conditions in the recent LFA-related studies to give detailed overview of the LFA development. We hope the review can give a general guide for the development of LFAs.
2018, 29(11): 1578-1584
doi: 10.1016/j.cclet.2017.12.009
Abstract:
With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces (APIs), which are membrane inlets (MIs), discontinuous atmospheric pressure interface (DAPI) and continuous atmospheric pressure interface (CAPI). This review emphasizes on the mini mass spectrometry (MS) system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.
With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces (APIs), which are membrane inlets (MIs), discontinuous atmospheric pressure interface (DAPI) and continuous atmospheric pressure interface (CAPI). This review emphasizes on the mini mass spectrometry (MS) system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.
2018, 29(11): 1585-1590
doi: 10.1016/j.cclet.2018.01.030
Abstract:
Cinchona alkaloid is one of the most effective organocatalysts that facilitate a wide range of transformations. To elucidate the mechanistic details and especially the origins of the observed high enantio-and diastereoselectivities, computational chemists have contributed dramatic efforts in this important area. This review covers the recent computational studies on the cinchona alkaloid-catalyzed asymmetric Michael additions, including both C-C and C-S bond formations, to present a general viewpoint of these fruitful advances. Based on the types of bond formation and the cinchona alkaloid catalysts, key information regarding the activation model and the origins of enantioselectivities is discussed.
Cinchona alkaloid is one of the most effective organocatalysts that facilitate a wide range of transformations. To elucidate the mechanistic details and especially the origins of the observed high enantio-and diastereoselectivities, computational chemists have contributed dramatic efforts in this important area. This review covers the recent computational studies on the cinchona alkaloid-catalyzed asymmetric Michael additions, including both C-C and C-S bond formations, to present a general viewpoint of these fruitful advances. Based on the types of bond formation and the cinchona alkaloid catalysts, key information regarding the activation model and the origins of enantioselectivities is discussed.
2018, 29(11): 1591-1600
doi: 10.1016/j.cclet.2018.03.005
Abstract:
The diphenyldiacetylene (DPDA) and the corresponding polymers has become one of hot research topics in the field of functional materials, due to its highly π-conjugated system and outstanding electrochemical properties. Compared with routine polydiacetylenes, polydiphenyldiacetylene (PDPDA) has wider π-extension within the whole polymer structure and a larger intermolecular stacking tendency. Since the preorganization of monomers is essential for the topochemical polymerization, we here introduce several self-assembled methods and external-templated methods for the proper alignment of DPDA. From the perspective of morphology, the monomer structures and external templates are two of the important factors towards polymerization. Based on its structure, PDPDA can become a promising intelligent material for various optoelectical applications, and specifically we summarize the application of PDPDA as an effective phtocatalyst in organic pollutants degradation
The diphenyldiacetylene (DPDA) and the corresponding polymers has become one of hot research topics in the field of functional materials, due to its highly π-conjugated system and outstanding electrochemical properties. Compared with routine polydiacetylenes, polydiphenyldiacetylene (PDPDA) has wider π-extension within the whole polymer structure and a larger intermolecular stacking tendency. Since the preorganization of monomers is essential for the topochemical polymerization, we here introduce several self-assembled methods and external-templated methods for the proper alignment of DPDA. From the perspective of morphology, the monomer structures and external templates are two of the important factors towards polymerization. Based on its structure, PDPDA can become a promising intelligent material for various optoelectical applications, and specifically we summarize the application of PDPDA as an effective phtocatalyst in organic pollutants degradation
2018, 29(11): 1601-1608
doi: 10.1016/j.cclet.2018.08.007
Abstract:
Synthesis of magnetic nanoparticles (MNPs) is one of the most active research areas in advanced materials. MNPs that have magnetic properties and other functionalities have been demonstrated to show great promise in nanomedical applications. This review summarizes the current MNPs preparation, functionalization and stabilization methods. It also analyzes the detailed features of MNPs. And furthermore it highlights some actual case analyses of these MNPs for disease therapy, drug delivery, hyperthermia, bioseparation and bioimaging applications.
Synthesis of magnetic nanoparticles (MNPs) is one of the most active research areas in advanced materials. MNPs that have magnetic properties and other functionalities have been demonstrated to show great promise in nanomedical applications. This review summarizes the current MNPs preparation, functionalization and stabilization methods. It also analyzes the detailed features of MNPs. And furthermore it highlights some actual case analyses of these MNPs for disease therapy, drug delivery, hyperthermia, bioseparation and bioimaging applications.
2018, 29(11): 1609-1612
doi: 10.1016/j.cclet.2018.02.010
Abstract:
Bone tumor is a refractory neoplastic growth of tissue in bone. According to the unique environment and phys-chemical characteristics of bone tissues, the chemotherapeutic agents are unlikely to prolong the survival of patients and often associated with systemic side effects. The bone targeting drug delivery via systemic administration may provide both better treatment efficacy and less frequent administration. In this study, we describe the synthesis, in vitro and in vivo evaluation of novel melphalan-bisphosphonate hybrids, with a tumor microenvironment sensitive linkage, which could be enzymatic activation under tumor microenvironment conditions. We have also evaluated the in vitro targeting efficiency of these prodrugs via the affinity of hydroxyapatite (HA) and cellular proliferation. The in vivo distribution suggested the bisphosphonate conjugated prodrugs with high bone selectivity.
Bone tumor is a refractory neoplastic growth of tissue in bone. According to the unique environment and phys-chemical characteristics of bone tissues, the chemotherapeutic agents are unlikely to prolong the survival of patients and often associated with systemic side effects. The bone targeting drug delivery via systemic administration may provide both better treatment efficacy and less frequent administration. In this study, we describe the synthesis, in vitro and in vivo evaluation of novel melphalan-bisphosphonate hybrids, with a tumor microenvironment sensitive linkage, which could be enzymatic activation under tumor microenvironment conditions. We have also evaluated the in vitro targeting efficiency of these prodrugs via the affinity of hydroxyapatite (HA) and cellular proliferation. The in vivo distribution suggested the bisphosphonate conjugated prodrugs with high bone selectivity.
2018, 29(11): 1613-1616
doi: 10.1016/j.cclet.2018.04.017
Abstract:
Three novel fluorinated cationic surfactants were prepared byadopting perfluoro-2-methyl-2-pentene as raw substrate. The as-obtained fluorinated cationic surfactants exhibited excellent surface properties, all of them can reduce the surface tension of water to below 20.00 mN/m at the critical micelle concentrations (CMC). The incorporation of SDS, AOS, APG or LAB into 2-(4-(3, 3, 4, 4, 5, 5, 5-heptafluoro-2, 2-bis(trifluoromethyl)pentyl)benzamido)-N, N-dimethylethana-mine oxide 4a could generate much lower CMC and surface tension value at the CMC than individual 4a. Especially, the surface tension values of that combined APG/4a can be reduced to 17.31 mN/m. The excellent surface activities and their remarkable compatibility to various types of hydrocarbon surfactants make them as sustainable alternatives to PFOA (perfluorooctanoic acid, C7F15CO2H) and PFOS (perfluorooctane sulphonate, C8F17SO3X, with X=K, Na, H).
Three novel fluorinated cationic surfactants were prepared byadopting perfluoro-2-methyl-2-pentene as raw substrate. The as-obtained fluorinated cationic surfactants exhibited excellent surface properties, all of them can reduce the surface tension of water to below 20.00 mN/m at the critical micelle concentrations (CMC). The incorporation of SDS, AOS, APG or LAB into 2-(4-(3, 3, 4, 4, 5, 5, 5-heptafluoro-2, 2-bis(trifluoromethyl)pentyl)benzamido)-N, N-dimethylethana-mine oxide 4a could generate much lower CMC and surface tension value at the CMC than individual 4a. Especially, the surface tension values of that combined APG/4a can be reduced to 17.31 mN/m. The excellent surface activities and their remarkable compatibility to various types of hydrocarbon surfactants make them as sustainable alternatives to PFOA (perfluorooctanoic acid, C7F15CO2H) and PFOS (perfluorooctane sulphonate, C8F17SO3X, with X=K, Na, H).
2018, 29(11): 1617-1620
doi: 10.1016/j.cclet.2018.03.030
Abstract:
The liquid-phase furfural (FAL) hydrogenation to furfuryl alcohol (FOL) and tetrahydrofurfuryl alcohol (THFOL) was investigated using sulfonate group (-SO3H) grafted activated carbon (AC) supported Ni catalyst, which was prepared and activated simultaneously by liquid phase reduction method. This functionalized nickel catalyst demonstrated an enhanced catalytic performance for selective hydrogenation of FAL, in which almost 100% FOL (< 80℃) and THFOL (>100℃) selectivity with complete conversion was obtained, respectively. More importantly, the conversion of transfer hydrogenation of FAL to FOL also can reach almost 100% under optimal conditions (140℃, 4.0 h). The effect of -SO3H was evaluated and systematically analyzed by the combination of reaction performance and physico-chemical characterizations. Cycling test proved the prepared catalyst could be recycled and reused for several times without noticeably reducing catalytic activity of hydrogenation.
The liquid-phase furfural (FAL) hydrogenation to furfuryl alcohol (FOL) and tetrahydrofurfuryl alcohol (THFOL) was investigated using sulfonate group (-SO3H) grafted activated carbon (AC) supported Ni catalyst, which was prepared and activated simultaneously by liquid phase reduction method. This functionalized nickel catalyst demonstrated an enhanced catalytic performance for selective hydrogenation of FAL, in which almost 100% FOL (< 80℃) and THFOL (>100℃) selectivity with complete conversion was obtained, respectively. More importantly, the conversion of transfer hydrogenation of FAL to FOL also can reach almost 100% under optimal conditions (140℃, 4.0 h). The effect of -SO3H was evaluated and systematically analyzed by the combination of reaction performance and physico-chemical characterizations. Cycling test proved the prepared catalyst could be recycled and reused for several times without noticeably reducing catalytic activity of hydrogenation.
2018, 29(11): 1621-1624
doi: 10.1016/j.cclet.2018.04.002
Abstract:
A new type of photo-induced supramolecular polymer was fabricated by host-guest interaction from a phototrigger containing building block. A dibenzo-24-crown-8 (DB24C8) macrocycle and dibenzylammonium (DBA) site containing linear monomer was designed and synthesized. The coumarin, as a photocleavable protector, was introduced to the terminal of the monomer. When exposed to the UV light, the coumarin unit would be cleavaged and the monomer without terminal coumarin can self-assemble into supramolecular polymers via the host-guest interaction between DB24C8 moieties and DBA units. Increasing the concentration of the monomer, the supramolecular polymers will convert to supramolecular organogel by cross-linking with each other.
A new type of photo-induced supramolecular polymer was fabricated by host-guest interaction from a phototrigger containing building block. A dibenzo-24-crown-8 (DB24C8) macrocycle and dibenzylammonium (DBA) site containing linear monomer was designed and synthesized. The coumarin, as a photocleavable protector, was introduced to the terminal of the monomer. When exposed to the UV light, the coumarin unit would be cleavaged and the monomer without terminal coumarin can self-assemble into supramolecular polymers via the host-guest interaction between DB24C8 moieties and DBA units. Increasing the concentration of the monomer, the supramolecular polymers will convert to supramolecular organogel by cross-linking with each other.
2018, 29(11): 1625-1628
doi: 10.1016/j.cclet.2018.01.026
Abstract:
A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7:1-20:1 dr under the catalysis of L-diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4-diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalytic asymmetric phosphaMichael addition of α, β-unsaturated aldehydes with pentavalent P-nucleophiles.
A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7:1-20:1 dr under the catalysis of L-diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4-diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalytic asymmetric phosphaMichael addition of α, β-unsaturated aldehydes with pentavalent P-nucleophiles.
2018, 29(11): 1629-1632
doi: 10.1016/j.cclet.2018.08.010
Abstract:
A simple and effective photoelectrochemical sensor was fabricated by Cu/graphitic carbon nitride (Cu/gCN) composites for detecting bisphenol A. The Cu/g-CN composites were obtained via a solvothermal process in the presence of the copper-based ionic liquid. In view of localized surface plasmon resonance of Cu nanoparticles, Cu nanoparticles can promote light absorbance and rapid electron transport of g-CN. As a result, the Cu/g-CN composites obtained greatly enhancement of photocurrent, when compared to the pure g-CN. In addition, the introduction of bisphenol A can hinder electron-hole recombination, resulting in sensitive photoelectrochemical monitoring of bisphenol A. The detection limit of the bisphenol A photoelectrochemical sensor was below 0.012 μmol/L. The bisphenol A photoelectrochemical sensor exhibited an excellent stability and acceptable anti-interference. The photoelectrochemical sensor provided the promising platform to monitor bisphenol A at low concentration in water environment.
A simple and effective photoelectrochemical sensor was fabricated by Cu/graphitic carbon nitride (Cu/gCN) composites for detecting bisphenol A. The Cu/g-CN composites were obtained via a solvothermal process in the presence of the copper-based ionic liquid. In view of localized surface plasmon resonance of Cu nanoparticles, Cu nanoparticles can promote light absorbance and rapid electron transport of g-CN. As a result, the Cu/g-CN composites obtained greatly enhancement of photocurrent, when compared to the pure g-CN. In addition, the introduction of bisphenol A can hinder electron-hole recombination, resulting in sensitive photoelectrochemical monitoring of bisphenol A. The detection limit of the bisphenol A photoelectrochemical sensor was below 0.012 μmol/L. The bisphenol A photoelectrochemical sensor exhibited an excellent stability and acceptable anti-interference. The photoelectrochemical sensor provided the promising platform to monitor bisphenol A at low concentration in water environment.
2018, 29(11): 1633-1636
doi: 10.1016/j.cclet.2018.01.055
Abstract:
Nano gold (Au) particles loaded carbon nanotubes (Nano-Au/CNTs) were prepared by a new method. Polar groups and defects were introduced on the surface of the prepared Nano-Au/CNTs by a mixed acids treatment process, and their electrocatalytic properties were investigated in this study. Comparing with the traditional preparation method, the particle nano size of Au can be controlled and it is easier to wash the sodium citrate by this method. Comparing t performance.
Nano gold (Au) particles loaded carbon nanotubes (Nano-Au/CNTs) were prepared by a new method. Polar groups and defects were introduced on the surface of the prepared Nano-Au/CNTs by a mixed acids treatment process, and their electrocatalytic properties were investigated in this study. Comparing with the traditional preparation method, the particle nano size of Au can be controlled and it is easier to wash the sodium citrate by this method. Comparing t performance.
2018, 29(11): 1637-1640
doi: 10.1016/j.cclet.2018.06.003
Abstract:
We describe the development of dinuclear metallic ligands to target specific HIV RNA structures. Two series of dipyridinyl-N bridged dinuclear metal complexes were synthesized in moderate to good yields and their binding activities toward TAR and RRE RNA were studied both experimentally and theoretically. The docking calculation elucidated some structure features in dimetallic complexes that can affect TAR RNA-binding properties.
We describe the development of dinuclear metallic ligands to target specific HIV RNA structures. Two series of dipyridinyl-N bridged dinuclear metal complexes were synthesized in moderate to good yields and their binding activities toward TAR and RRE RNA were studied both experimentally and theoretically. The docking calculation elucidated some structure features in dimetallic complexes that can affect TAR RNA-binding properties.
2018, 29(11): 1641-1644
doi: 10.1016/j.cclet.2018.02.005
Abstract:
Here, we report the direct hydrothermal synthesis of 1D-based Zn2GeO4:Mn2+ persistent luminescent nanobelts (ZGO:Mn PLNBs). The ZGO:Mn PLNBs exhibit rapid growth rate, and nanobelts can be obtained after 30 min of hydrothermal treatment. The persistent luminescence performance can be fine-turned upon prolonging the hydrothermal time. Furthermore, the doping ratio of Mn2+ exhibits influence on the persistent luminescence properties of ZGO:Mn PLNBs, and 2% doping of Mn2+ shows superior persistent luminescence with decay time of longer than 20 min. The developed 1D-based ZGO:Mn PLNBs can be simply prepared with the hydrothermal method and show tunable morphology and persistent luminescence. We believe that this solid-state-reaction-free chemical approach avoids the current key drawback in regard to PLNMs development, and thus will promote the broad use of these unique nanostructured PLNMs in developing optical device for imaging.
Here, we report the direct hydrothermal synthesis of 1D-based Zn2GeO4:Mn2+ persistent luminescent nanobelts (ZGO:Mn PLNBs). The ZGO:Mn PLNBs exhibit rapid growth rate, and nanobelts can be obtained after 30 min of hydrothermal treatment. The persistent luminescence performance can be fine-turned upon prolonging the hydrothermal time. Furthermore, the doping ratio of Mn2+ exhibits influence on the persistent luminescence properties of ZGO:Mn PLNBs, and 2% doping of Mn2+ shows superior persistent luminescence with decay time of longer than 20 min. The developed 1D-based ZGO:Mn PLNBs can be simply prepared with the hydrothermal method and show tunable morphology and persistent luminescence. We believe that this solid-state-reaction-free chemical approach avoids the current key drawback in regard to PLNMs development, and thus will promote the broad use of these unique nanostructured PLNMs in developing optical device for imaging.
2018, 29(11): 1645-1647
doi: 10.1016/j.cclet.2018.01.056
Abstract:
A self-assembling bis-pyrene (BP) molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized by using differential scanning calorimetry (DSC), polarized optical microscope (POM), and 1D wide angle X-ray diffraction (WAXD) techniques. In solution, the BP self-assembled into nanofibers in the mixed dichloromethane and hexane (1:1 volume ratio) solvent. Interestingly, the BP was not fluorescent when dissolved in dichloromethane solution. However, the self-assembled nanostructures of BP in the mixed solvent showed high intensity of green fluorescence. The advantages of self-assembly and fluorescence feature exhibited that BP could be promising fluorescence nanoprobes or nanosensors for various applications.
A self-assembling bis-pyrene (BP) molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized by using differential scanning calorimetry (DSC), polarized optical microscope (POM), and 1D wide angle X-ray diffraction (WAXD) techniques. In solution, the BP self-assembled into nanofibers in the mixed dichloromethane and hexane (1:1 volume ratio) solvent. Interestingly, the BP was not fluorescent when dissolved in dichloromethane solution. However, the self-assembled nanostructures of BP in the mixed solvent showed high intensity of green fluorescence. The advantages of self-assembly and fluorescence feature exhibited that BP could be promising fluorescence nanoprobes or nanosensors for various applications.
2018, 29(11): 1648-1650
doi: 10.1016/j.cclet.2018.01.025
Abstract:
Spirotetramat metabolizes to its active enol form in the plant. We described here a photocaged pesticide delivery system that can release insecticidal spirotetramat enol form upon light irradiation. Covalently linking spirotetramat-enol with photoresponsive coumarin generated the caged insecticide. The photophysical and photochemical properties, deprotection photolysis and insecticidal activities of the caged spirotetramat enol were studied. This light-triggered system can undergo cleavage to release free spirotetramat enol form at the presence of blue light (420 nm) or sunlight. Bioassays indicated that the triggered molecule has no obvious insecticidal activity against Aphis craccivora Koch at dark and could be activated by light to release the insecticidal ingredients, which provides precise control over insecticide delivery.
Spirotetramat metabolizes to its active enol form in the plant. We described here a photocaged pesticide delivery system that can release insecticidal spirotetramat enol form upon light irradiation. Covalently linking spirotetramat-enol with photoresponsive coumarin generated the caged insecticide. The photophysical and photochemical properties, deprotection photolysis and insecticidal activities of the caged spirotetramat enol were studied. This light-triggered system can undergo cleavage to release free spirotetramat enol form at the presence of blue light (420 nm) or sunlight. Bioassays indicated that the triggered molecule has no obvious insecticidal activity against Aphis craccivora Koch at dark and could be activated by light to release the insecticidal ingredients, which provides precise control over insecticide delivery.
2018, 29(11): 1651-1655
doi: 10.1016/j.cclet.2018.03.013
Abstract:
A series of {2Fe3S} complexes bearing phosphino thioether chelating ligand were synthesized on the basis of Fe2(Me2pdt)(1, 2-Cy2PC6H4SMe)(CO)4 (Me2pdt=Me2C(CH2S-)2, 1). The disubstituted Fe(Ⅰ)Fe(Ⅰ) compound 1 exhibits a reversible one-electron redox even for[Fe(Ⅰ)Fe(Ⅱ)]+/0 couple. Based on the oxidation of 1 to[1]+, the tri-substituted[Fe(Ⅰ)Fe(Ⅱ)]+ cationic complex[Fe2(Me2pdt)(1, 2-Cy2PC6H4SMe) (PPh3)(CO)3]+ ([2]+) was synthesized. Reduction of[2]+ provided the neutral tri-substituted Fe(Ⅰ)Fe(Ⅰ) compound 2. The substitution of the CO in 1 ligand by PPh3 results in an anodic shift of the FeⅡFeI/FeIFeI couple of 470 mV. Most importantly, this substitution also leads to the Fe-Fe bonds in 1 and 2 with large Lewis basicity difference, i.e. △pKaMeCN~10.
A series of {2Fe3S} complexes bearing phosphino thioether chelating ligand were synthesized on the basis of Fe2(Me2pdt)(1, 2-Cy2PC6H4SMe)(CO)4 (Me2pdt=Me2C(CH2S-)2, 1). The disubstituted Fe(Ⅰ)Fe(Ⅰ) compound 1 exhibits a reversible one-electron redox even for[Fe(Ⅰ)Fe(Ⅱ)]+/0 couple. Based on the oxidation of 1 to[1]+, the tri-substituted[Fe(Ⅰ)Fe(Ⅱ)]+ cationic complex[Fe2(Me2pdt)(1, 2-Cy2PC6H4SMe) (PPh3)(CO)3]+ ([2]+) was synthesized. Reduction of[2]+ provided the neutral tri-substituted Fe(Ⅰ)Fe(Ⅰ) compound 2. The substitution of the CO in 1 ligand by PPh3 results in an anodic shift of the FeⅡFeI/FeIFeI couple of 470 mV. Most importantly, this substitution also leads to the Fe-Fe bonds in 1 and 2 with large Lewis basicity difference, i.e. △pKaMeCN~10.
2018, 29(11): 1656-1660
doi: 10.1016/j.cclet.2018.06.017
Abstract:
Metal oxide anode material is one of promising candidates for the next-generation LIBs, due to its high theoretical capacity and low cost. The poor conductivity and huge volume change during charge/discharge, however, restrict the commercialization of metal oxide anode material. In this work, we design a novel Cu-SnO2 composite derived from Cu6Sn5 alloy with three dimensional (3D) metal cluster conducting architecture. The novel Cu structure penetrates in the composite particles inducing high conductivity and space-confined SnO2, which restrict the pulverization of SnO2 during lithiation/delithiation process. The optimized Cu-SnO2 composite anode delivers an initial discharge capacity of 933.7 mA h/g and retains a capacity of 536.1 mA h/g after 200 cycles, at 25℃ and a rate of 100 mA/g. Even at the high rate of 300 mA/g, the anode still exhibits a capacity of more than 29% of that tested at 50 mA/g. Combining with the phase and morphology analysis, the novel Cu-SnO2 composite not only has good electrical conductivity, but also possesses high theoretical capacity (995 mAh/g), which may pave a new way for the design and construction of next-generation metal oxide anode materials with high power and cycling stability.
Metal oxide anode material is one of promising candidates for the next-generation LIBs, due to its high theoretical capacity and low cost. The poor conductivity and huge volume change during charge/discharge, however, restrict the commercialization of metal oxide anode material. In this work, we design a novel Cu-SnO2 composite derived from Cu6Sn5 alloy with three dimensional (3D) metal cluster conducting architecture. The novel Cu structure penetrates in the composite particles inducing high conductivity and space-confined SnO2, which restrict the pulverization of SnO2 during lithiation/delithiation process. The optimized Cu-SnO2 composite anode delivers an initial discharge capacity of 933.7 mA h/g and retains a capacity of 536.1 mA h/g after 200 cycles, at 25℃ and a rate of 100 mA/g. Even at the high rate of 300 mA/g, the anode still exhibits a capacity of more than 29% of that tested at 50 mA/g. Combining with the phase and morphology analysis, the novel Cu-SnO2 composite not only has good electrical conductivity, but also possesses high theoretical capacity (995 mAh/g), which may pave a new way for the design and construction of next-generation metal oxide anode materials with high power and cycling stability.
2018, 29(11): 1661-1665
doi: 10.1016/j.cclet.2018.06.023
Abstract:
Photo-responsive azobenzene (ABZ) derivatives with different end groups (R) as photoswitchable molecules were employed to construct self-assembled monolayers (SAMs) on silicon substrate by using 3-glycidoxypropyltrimethoxysilane (GPTS) as the bridging molecules. The assembly process was optimized by changing various parameters, including the type and concentration of ABZ derivatives, reaction time, etc. The obtained SAMs were fully characterized and evaluated using UV spectroscopy, atomic force microscope (AFM), elllipsometer, static contact angle and X-ray photoelectron spectroscopy (XPS). It is found that the end group property of azobenzene derivatives is critical to the obtained SAMs' photoresponsive properties. Compared with hydrophobic compounds (4-(4'-aminophenylazo) benzoic acid, ABZ-CF3), the hydrophilic compounds (4-(4'-aminophenylazo) benzoic acid, ABZ-COOH) show excellent reversible photoswitching performance with a large contact angle change of 35° under optimized process, and the SAMs are removable by thermal treatment at 240℃ in air for only 5 min.
Photo-responsive azobenzene (ABZ) derivatives with different end groups (R) as photoswitchable molecules were employed to construct self-assembled monolayers (SAMs) on silicon substrate by using 3-glycidoxypropyltrimethoxysilane (GPTS) as the bridging molecules. The assembly process was optimized by changing various parameters, including the type and concentration of ABZ derivatives, reaction time, etc. The obtained SAMs were fully characterized and evaluated using UV spectroscopy, atomic force microscope (AFM), elllipsometer, static contact angle and X-ray photoelectron spectroscopy (XPS). It is found that the end group property of azobenzene derivatives is critical to the obtained SAMs' photoresponsive properties. Compared with hydrophobic compounds (4-(4'-aminophenylazo) benzoic acid, ABZ-CF3), the hydrophilic compounds (4-(4'-aminophenylazo) benzoic acid, ABZ-COOH) show excellent reversible photoswitching performance with a large contact angle change of 35° under optimized process, and the SAMs are removable by thermal treatment at 240℃ in air for only 5 min.
2018, 29(11): 1666-1670
doi: 10.1016/j.cclet.2018.05.044
Abstract:
Biogenic single crystals have been widely demonstrated to incorporate macromolecules to achieve extra damage tolerance, spurring investigations on their synthetic analogs with enhanced mechanical properties as well as the enhancement mechanism(s) behind. And the investigations rely on both rational design of the single-crystal composites and, equally importantly, nanoscale and in-situ characterization strategy. Here, composite structures are constructed inside the calcite single-crystal host by incorporating guest materials of agarose fibers, multi-walled carbon nanotubes (MWCNTs), and graphene oxide (GO), through crystallization in agarose gel media. Further, transmission electron microscopy-scanning probe microscopy (TEM-SPM) method, coupling compression measurements with nanoscale imaging, shows that the obtained single-crystal composites exhibit improved toughness, compared to the solution-grown pure single crystals. Particularly, the rupture time increases by 1.25 times after the gel-networks and MWCNTs are incorporated. More importantly, the in-situ observation of the crystal deformation suggests that the guest incorporation toughens the single-crystal host by the shielding effect of nanofiber on crack-bridging at nanoscale. As such, this work may have implications for understanding the damage tolerance of biominerals as well as towards the development of new mechanically reinforced single-crystal composite materials.
Biogenic single crystals have been widely demonstrated to incorporate macromolecules to achieve extra damage tolerance, spurring investigations on their synthetic analogs with enhanced mechanical properties as well as the enhancement mechanism(s) behind. And the investigations rely on both rational design of the single-crystal composites and, equally importantly, nanoscale and in-situ characterization strategy. Here, composite structures are constructed inside the calcite single-crystal host by incorporating guest materials of agarose fibers, multi-walled carbon nanotubes (MWCNTs), and graphene oxide (GO), through crystallization in agarose gel media. Further, transmission electron microscopy-scanning probe microscopy (TEM-SPM) method, coupling compression measurements with nanoscale imaging, shows that the obtained single-crystal composites exhibit improved toughness, compared to the solution-grown pure single crystals. Particularly, the rupture time increases by 1.25 times after the gel-networks and MWCNTs are incorporated. More importantly, the in-situ observation of the crystal deformation suggests that the guest incorporation toughens the single-crystal host by the shielding effect of nanofiber on crack-bridging at nanoscale. As such, this work may have implications for understanding the damage tolerance of biominerals as well as towards the development of new mechanically reinforced single-crystal composite materials.
2018, 29(11): 1671-1674
doi: 10.1016/j.cclet.2018.04.009
Abstract:
The development of highly active noble-metal-free catalysts for catalytic hydrolysis of ammonia borane is mandatory for its application in hydrogen storage. Herein, Co-CeOx nanoclusters have been successfully anchored on a three-dimensional nitrogen-doped graphene hydrogel (NGH) by a simple coreduction method and further used as efficient catalysts to catalytic hydrolysis of ammonia borane at room temperature. Thanks to the strong synergistic electronic effect between Co and CeOx, as well as the strong metal-support interaction between Co-CeOx and 3D NGH, the as-synthesized Co-(CeOx)0.91/NGH catalyst exhibits superior catalytic activity toward hydrolysis of ammonia borane, with the turnover frequency (TOF) value of 79.5 min-1, which is almost 13 times higher than that of Co/NGH, and higher than most of the reported noble-metal-free catalysts.
The development of highly active noble-metal-free catalysts for catalytic hydrolysis of ammonia borane is mandatory for its application in hydrogen storage. Herein, Co-CeOx nanoclusters have been successfully anchored on a three-dimensional nitrogen-doped graphene hydrogel (NGH) by a simple coreduction method and further used as efficient catalysts to catalytic hydrolysis of ammonia borane at room temperature. Thanks to the strong synergistic electronic effect between Co and CeOx, as well as the strong metal-support interaction between Co-CeOx and 3D NGH, the as-synthesized Co-(CeOx)0.91/NGH catalyst exhibits superior catalytic activity toward hydrolysis of ammonia borane, with the turnover frequency (TOF) value of 79.5 min-1, which is almost 13 times higher than that of Co/NGH, and higher than most of the reported noble-metal-free catalysts.
2018, 29(11): 1675-1680
doi: 10.1016/j.cclet.2018.03.034
Abstract:
Conjugated polymers have received considerable attentions over the past years due to their large-area potential applications via low-cost solution processing. Improving crystallinity of conjugated polymer molecules in solution-processed thin films is crucial for their efficient charge transport and thus high performance optoelectronic devices. Herein, with diketopyrrolopyrrole-quaterthiophene (PDQT) copolymer as an example, it is found that by simply reducing the solution concentration for spincoating meanwhile with the assistance of post-annealing, significantly enhanced film crystallinity with formation of typical single crystalline domains is obtained, which benefits from the enough space for better molecular assembly especially at the semiconductor/dielectric interface. High performance polymer transistors and phototransistors were finally constructed based on the optimal lowconcentration (2 mg/mL) spin-coated PDQT films (~12 nm), which giving a high charge carrier mobility of 2.28 cm2 V-1 s-1 and a photoresponse on/off ratio of 2.1×107 at VG=0 V under white light irradiation of 6 mW/cm2. The results suggest that the bright future of PDQT crystalline films for large-area flexible integrated optoelectronic devices and the application of effective low-concentration processing approach in solution-processed organic electronics with reduced material waste.
Conjugated polymers have received considerable attentions over the past years due to their large-area potential applications via low-cost solution processing. Improving crystallinity of conjugated polymer molecules in solution-processed thin films is crucial for their efficient charge transport and thus high performance optoelectronic devices. Herein, with diketopyrrolopyrrole-quaterthiophene (PDQT) copolymer as an example, it is found that by simply reducing the solution concentration for spincoating meanwhile with the assistance of post-annealing, significantly enhanced film crystallinity with formation of typical single crystalline domains is obtained, which benefits from the enough space for better molecular assembly especially at the semiconductor/dielectric interface. High performance polymer transistors and phototransistors were finally constructed based on the optimal lowconcentration (2 mg/mL) spin-coated PDQT films (~12 nm), which giving a high charge carrier mobility of 2.28 cm2 V-1 s-1 and a photoresponse on/off ratio of 2.1×107 at VG=0 V under white light irradiation of 6 mW/cm2. The results suggest that the bright future of PDQT crystalline films for large-area flexible integrated optoelectronic devices and the application of effective low-concentration processing approach in solution-processed organic electronics with reduced material waste.
2018, 29(11): 1681-1684
doi: 10.1016/j.cclet.2018.07.015
Abstract:
The development of fabrication method for flexible thin organic electronic device is highly important for the flexible and wearable products. Herein, we develop a facile peel-off method to transfer organic thin film to various substrates. In this strategy, polyacrylonitrile (PAN) film can be easily peeled off with trace water and further transferred to various substrates. Using PAN as supporting and dielectric layers, high performance flexible organic transistors are fabricated. Remarkably, the method uses only micro volume water as an assist to peel off PAN film, which reduces the risk of contamination by solvent and greatly contributes to the performance maintenance.
The development of fabrication method for flexible thin organic electronic device is highly important for the flexible and wearable products. Herein, we develop a facile peel-off method to transfer organic thin film to various substrates. In this strategy, polyacrylonitrile (PAN) film can be easily peeled off with trace water and further transferred to various substrates. Using PAN as supporting and dielectric layers, high performance flexible organic transistors are fabricated. Remarkably, the method uses only micro volume water as an assist to peel off PAN film, which reduces the risk of contamination by solvent and greatly contributes to the performance maintenance.
2018, 29(11): 1685-1688
doi: 10.1016/j.cclet.2017.12.004
Abstract:
More recently, the biomedical applications of MnO2 in bioanalysis, cell imaging, and drug delivery as a result of their appealing physicochemical properties, have been reported and expanded rapidly. However, research on a near infrared (NIR) photothermal response of MnO2 was ignored. In this work, we reported a facile, one-pot method to synthesis of bovine serum albumin (BSA)-reduced and stabilized MnO2 nanoparticles (BSA-MnO2 NPs) with good aqueous dispersibility and high biocompatibility. And we also showed for the first time that BSA-MnO2 NPs displayed superior NIR photothermal efficiency and photostability which demonstrated as a novel class of photothermal antitumor agent.
More recently, the biomedical applications of MnO2 in bioanalysis, cell imaging, and drug delivery as a result of their appealing physicochemical properties, have been reported and expanded rapidly. However, research on a near infrared (NIR) photothermal response of MnO2 was ignored. In this work, we reported a facile, one-pot method to synthesis of bovine serum albumin (BSA)-reduced and stabilized MnO2 nanoparticles (BSA-MnO2 NPs) with good aqueous dispersibility and high biocompatibility. And we also showed for the first time that BSA-MnO2 NPs displayed superior NIR photothermal efficiency and photostability which demonstrated as a novel class of photothermal antitumor agent.
2018, 29(11): 1689-1691
doi: 10.1016/j.cclet.2017.12.016
Abstract:
BiOI microspheres were synthesized via a facile hydrolytic method with sodium dodecyl sulfate (SDS). The results showed that 8% SDS-BiOI microspheres possessed the homogeneous morphology, larger specific surface area and more oxygen vacancies compared with the pure BiOI. Moreover, the adsorption efficiency of rhodamine B (RhB) and methyl orange (MO) for 8% SDS-BiOI reached almost 96.4% and 79.4%, respectively. It was found that the oxygen vacancy induced by SDS improved adsorption performance of BiOI due to the enhanced electrostatic interaction.
BiOI microspheres were synthesized via a facile hydrolytic method with sodium dodecyl sulfate (SDS). The results showed that 8% SDS-BiOI microspheres possessed the homogeneous morphology, larger specific surface area and more oxygen vacancies compared with the pure BiOI. Moreover, the adsorption efficiency of rhodamine B (RhB) and methyl orange (MO) for 8% SDS-BiOI reached almost 96.4% and 79.4%, respectively. It was found that the oxygen vacancy induced by SDS improved adsorption performance of BiOI due to the enhanced electrostatic interaction.
2018, 29(11): 1692-1697
doi: 10.1016/j.cclet.2017.12.015
Abstract:
The strategy of N-doping in carbon materials could provide additional Li-ion storage sites to improve their electrochemical properties. Heteroatom-containing polymers could serve as good precursors to fabricate doped carbons due to the capability to in situ dope heteroatoms into the structures. In this work, electrospun heterocyclic polyimide (PI) nanofiber membranes containing biphenyl and pyrimidine rings were carbonized to fabricate freestanding and flexible heteroatoms-containing carbon membranes. When the polymer membranes were subjected to various calcination temperatures (from 550℃ to 950℃) and durations (0.5-10 h), the structural evolutions strongly affect their electrochemical properties as anodes for lithium ion batteries. It demonstrated that the reversible specific capacity of obtained sample treated at 650℃ for 3 h could achieve 695 mAh/g at 0.1 A/g and retain 245 mAh/g at 1.5 A/g after 300 cycles. Furthermore, the electrospun membrane maintains a good electrochemical performance at bending state as a flexible electrode.
The strategy of N-doping in carbon materials could provide additional Li-ion storage sites to improve their electrochemical properties. Heteroatom-containing polymers could serve as good precursors to fabricate doped carbons due to the capability to in situ dope heteroatoms into the structures. In this work, electrospun heterocyclic polyimide (PI) nanofiber membranes containing biphenyl and pyrimidine rings were carbonized to fabricate freestanding and flexible heteroatoms-containing carbon membranes. When the polymer membranes were subjected to various calcination temperatures (from 550℃ to 950℃) and durations (0.5-10 h), the structural evolutions strongly affect their electrochemical properties as anodes for lithium ion batteries. It demonstrated that the reversible specific capacity of obtained sample treated at 650℃ for 3 h could achieve 695 mAh/g at 0.1 A/g and retain 245 mAh/g at 1.5 A/g after 300 cycles. Furthermore, the electrospun membrane maintains a good electrochemical performance at bending state as a flexible electrode.
2018, 29(11): 1698-1701
doi: 10.1016/j.cclet.2018.01.004
Abstract:
Graphene quantum dots (GQDs) recently emerge as the new and appealing nanophotocatalyst because of their low-cost, environmental compatibility and the ability to facilitate the charge migration and prolong the charge lifetimes. In this work, a visible photocatalyst of S-doped graphene quantum dots (S-GQDs) was prepared by a facile hydrothermal synthesis using 1, 3, 6-trinitropyrene and Na2S as precursors. The well crystallization and monodispersity as well as the chemical environment of S-GQDs were characterized by transmission electron microscopy, atom force microscopy and X-ray photoelectron spectrum. A superior photocatalytic performance of S-GQDs was demonstrated for degradation of basic fuchsin under visible light irradiation. Furthermore, the possible photocatalytic mechanism was proposed based on the trapping experiments of active species.
Graphene quantum dots (GQDs) recently emerge as the new and appealing nanophotocatalyst because of their low-cost, environmental compatibility and the ability to facilitate the charge migration and prolong the charge lifetimes. In this work, a visible photocatalyst of S-doped graphene quantum dots (S-GQDs) was prepared by a facile hydrothermal synthesis using 1, 3, 6-trinitropyrene and Na2S as precursors. The well crystallization and monodispersity as well as the chemical environment of S-GQDs were characterized by transmission electron microscopy, atom force microscopy and X-ray photoelectron spectrum. A superior photocatalytic performance of S-GQDs was demonstrated for degradation of basic fuchsin under visible light irradiation. Furthermore, the possible photocatalytic mechanism was proposed based on the trapping experiments of active species.
