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2019 Volume 30 Issue 5
2019, 30(5): 937-941
doi: 10.1016/j.cclet.2019.01.012
Abstract:
Deoximation reaction is one of the most important transformations in organic synthesis and for fine chemical production. Since oximes are easily synthesized from carbonyl compounds and are stable compounds, this reaction can be used for protection-deprotection, purification, and characterization of carbonyl compounds in organic synthesis, especially for the synthesis of medicines as well as the natural products. Moreover, because many oximes can be synthesized from non-carbonyl starting materials, the deoximation reaction is also widely used in the production of many carbonyl-contained fine chemicals. Deoximation methods by using stoichiometric reagents are mature and can produce the related carbonyl products in very high yield with broad substrate application scopes. But for environment-protection consideration as well as the production cost controlling purpose in fine chemical industry, developing catalytic deoximation methods is the trend of the field and there are a series of references on this topic in recent years. This short review summarized recent advances on the development of deoximation methods from stoichiometric reaction to catalytic reaction and the mechanisms of some important transformations were discussed in detail for reader reference.
Deoximation reaction is one of the most important transformations in organic synthesis and for fine chemical production. Since oximes are easily synthesized from carbonyl compounds and are stable compounds, this reaction can be used for protection-deprotection, purification, and characterization of carbonyl compounds in organic synthesis, especially for the synthesis of medicines as well as the natural products. Moreover, because many oximes can be synthesized from non-carbonyl starting materials, the deoximation reaction is also widely used in the production of many carbonyl-contained fine chemicals. Deoximation methods by using stoichiometric reagents are mature and can produce the related carbonyl products in very high yield with broad substrate application scopes. But for environment-protection consideration as well as the production cost controlling purpose in fine chemical industry, developing catalytic deoximation methods is the trend of the field and there are a series of references on this topic in recent years. This short review summarized recent advances on the development of deoximation methods from stoichiometric reaction to catalytic reaction and the mechanisms of some important transformations were discussed in detail for reader reference.
2019, 30(5): 942-948
doi: 10.1016/j.cclet.2019.01.015
Abstract:
In this study, a series of epoxy-based azo molecular glasses with four-arm architecture was synthesized based on an intermediate (MDGA-AN), which was obtained from ring-opening reaction between 4, 4'-methylene-bis(N, N'-diglycidylaniline) and N-methylaniline. The azo compounds were then synthesized through azo-coupling reaction between MDGA-AN and diazonium salts of 4-nitroaniline, 4-aminobenzonitrile, 4-aminobenzoic acid, 4-fluoroaniline and 4-methoxyaniline, respectively. The azo compounds were thoroughly characterized and the photoresponsive properties of their solid films were investigated at three different wavelengths (λex=488, 532 and 589 nm). The results show that the electron-withdrawing groups on the azo chromophores can significantly affect the absorption band positions in visible light range, which shift to the longer wavelength with the enhanced push-pull effect. Both photoinduced birefringence and surface-relief-grating formation are closely related to the electronwithdrawing groups and excitation wavelengths of the actinic light, which show significant influences on the growth rates and saturated values of the photoinduced variations. In this series, the azo molecular glasses containing cyano and carboxyl groups as the electron-withdrawing groups show the significantly higher efficiency for both the photoinduced birefringence growth and the SRG formation compared with others under the same light irradiation conditions. The capability of the materials as a photo-storage medium is demonstrated by holographic recording.
In this study, a series of epoxy-based azo molecular glasses with four-arm architecture was synthesized based on an intermediate (MDGA-AN), which was obtained from ring-opening reaction between 4, 4'-methylene-bis(N, N'-diglycidylaniline) and N-methylaniline. The azo compounds were then synthesized through azo-coupling reaction between MDGA-AN and diazonium salts of 4-nitroaniline, 4-aminobenzonitrile, 4-aminobenzoic acid, 4-fluoroaniline and 4-methoxyaniline, respectively. The azo compounds were thoroughly characterized and the photoresponsive properties of their solid films were investigated at three different wavelengths (λex=488, 532 and 589 nm). The results show that the electron-withdrawing groups on the azo chromophores can significantly affect the absorption band positions in visible light range, which shift to the longer wavelength with the enhanced push-pull effect. Both photoinduced birefringence and surface-relief-grating formation are closely related to the electronwithdrawing groups and excitation wavelengths of the actinic light, which show significant influences on the growth rates and saturated values of the photoinduced variations. In this series, the azo molecular glasses containing cyano and carboxyl groups as the electron-withdrawing groups show the significantly higher efficiency for both the photoinduced birefringence growth and the SRG formation compared with others under the same light irradiation conditions. The capability of the materials as a photo-storage medium is demonstrated by holographic recording.
2019, 30(5): 949-952
doi: 10.1016/j.cclet.2018.12.029
Abstract:
Multi-color and white light luminescence materials based on supramolecular assemblies are attractive because of their potential applications in advanced light-emitting material. Herein, a cucurbit[8]urilenhanced lanthanide luminescent supramolecular assembly was constructed in a facile but efficient way using terpyridine imidozalium cations, cucurbit[8]urils and rare earth ions such as Tb3+ and Eu3+. Significantly, the resultant fibrous supramolecular assembly, with an average width of 15 nm, could emit remarkable lanthanide luminescence, which was ten times higher than the corresponding terpyridine/Ln3+ without cucurbit[8]uril. And the solid state luminescence of supramolecular assembly could be smartly and easily turned among blue, green, red and white by adjusting the molar ratios between Tb3+ and Eu3+. The enhanced white-light emission by supramolecular strategy may provide a new approach for smart and tunable solid luminescent materials.
Multi-color and white light luminescence materials based on supramolecular assemblies are attractive because of their potential applications in advanced light-emitting material. Herein, a cucurbit[8]urilenhanced lanthanide luminescent supramolecular assembly was constructed in a facile but efficient way using terpyridine imidozalium cations, cucurbit[8]urils and rare earth ions such as Tb3+ and Eu3+. Significantly, the resultant fibrous supramolecular assembly, with an average width of 15 nm, could emit remarkable lanthanide luminescence, which was ten times higher than the corresponding terpyridine/Ln3+ without cucurbit[8]uril. And the solid state luminescence of supramolecular assembly could be smartly and easily turned among blue, green, red and white by adjusting the molar ratios between Tb3+ and Eu3+. The enhanced white-light emission by supramolecular strategy may provide a new approach for smart and tunable solid luminescent materials.
2019, 30(5): 953-956
doi: 10.1016/j.cclet.2019.02.010
Abstract:
The crystal structures of three intramolecularly hydrogen bonded rigid aromatic amide derivatives, which all bear one iodine atom at one end as the donor and one pyridine unit at the other end as the acceptor, have been described to reveal the utility of halogen bonding in inducing the formation of supramolecular macrocycles. All the three compounds formed intermolecular I…N halogen bonding. For short compound 1, halogen bonding induced the formation of an extended supramolecular array. For longer folded compounds 2 and 3, halogen bonding could hold two molecules to form supramolecular macrocycles even by adopting a highly distorted, energetically less favorable conformation (for 3). Depending on the solvent for the growth of crystals, compound 3 could also gave rise to a halogen bonded supramolecular double helix.
The crystal structures of three intramolecularly hydrogen bonded rigid aromatic amide derivatives, which all bear one iodine atom at one end as the donor and one pyridine unit at the other end as the acceptor, have been described to reveal the utility of halogen bonding in inducing the formation of supramolecular macrocycles. All the three compounds formed intermolecular I…N halogen bonding. For short compound 1, halogen bonding induced the formation of an extended supramolecular array. For longer folded compounds 2 and 3, halogen bonding could hold two molecules to form supramolecular macrocycles even by adopting a highly distorted, energetically less favorable conformation (for 3). Depending on the solvent for the growth of crystals, compound 3 could also gave rise to a halogen bonded supramolecular double helix.
2019, 30(5): 961-965
doi: 10.1016/j.cclet.2019.01.008
Abstract:
Self-healing materials have been developed over the past decade with the recovery ability after damage. However, most researches focused on the self-healing process at three-dimension. Herein, we prepare monolayer self-healing hydrogen-bond-based supramolecular polymer film and explore the self-healing process at the two-dimensional limit. The healing process, which can be reversibly repeated for at least three times, is influenced by the temperature, the molecule-substrate interaction and the substrate roughness. In the application, the monolayer self-healing polymer film can be used to modify the SiO2 dielectric for copper phthalocyanine field effect transistor with improved mobility. This work will be valuable for developing two-dimensional functional self-healing materials in the future.
Self-healing materials have been developed over the past decade with the recovery ability after damage. However, most researches focused on the self-healing process at three-dimension. Herein, we prepare monolayer self-healing hydrogen-bond-based supramolecular polymer film and explore the self-healing process at the two-dimensional limit. The healing process, which can be reversibly repeated for at least three times, is influenced by the temperature, the molecule-substrate interaction and the substrate roughness. In the application, the monolayer self-healing polymer film can be used to modify the SiO2 dielectric for copper phthalocyanine field effect transistor with improved mobility. This work will be valuable for developing two-dimensional functional self-healing materials in the future.
2019, 30(5): 966-968
doi: 10.1016/j.cclet.2019.02.015
Abstract:
Glycyrrhizic acid (GA), as a traditional herbal, can self-assemble into helical nanofiber in the water. The formed helical nanostructures can be employed as scaffolds for asymmetric Diels-Alder reaction. Through co-assembling with a series of achiral copper-ligands, the chirality of GA helical nanostructures can be transferred to catalytic site, and resulted assemblies showed moderated enantioselectivity toward catalysis of Diels-Alder reaction.
Glycyrrhizic acid (GA), as a traditional herbal, can self-assemble into helical nanofiber in the water. The formed helical nanostructures can be employed as scaffolds for asymmetric Diels-Alder reaction. Through co-assembling with a series of achiral copper-ligands, the chirality of GA helical nanostructures can be transferred to catalytic site, and resulted assemblies showed moderated enantioselectivity toward catalysis of Diels-Alder reaction.
2019, 30(5): 969-972
doi: 10.1016/j.cclet.2019.02.011
Abstract:
A copper-catalyzed α-selective C-H trifluoromethylation of acrylamides with TMSCF3 is described. A wide range of arenes and heteroarenes at the β-position of acrylamides are compatible with the reaction, affording the corresponding (E)-trifluoromethylated products in moderate to good yields. The reaction proceeded fast and can be completed within 30 min.
A copper-catalyzed α-selective C-H trifluoromethylation of acrylamides with TMSCF3 is described. A wide range of arenes and heteroarenes at the β-position of acrylamides are compatible with the reaction, affording the corresponding (E)-trifluoromethylated products in moderate to good yields. The reaction proceeded fast and can be completed within 30 min.
2019, 30(5): 973-976
doi: 10.1016/j.cclet.2019.01.006
Abstract:
A continuous-flow synthesis of nitriles by Schmidt reaction has been developed. Using this procedure, a variety of aldehydes could be smoothly transformed into the desired nitriles in good to excellent yields. The mild reaction conditions and the flowing reaction system greatly improved the safety and make the reaction easy to scale up.
A continuous-flow synthesis of nitriles by Schmidt reaction has been developed. Using this procedure, a variety of aldehydes could be smoothly transformed into the desired nitriles in good to excellent yields. The mild reaction conditions and the flowing reaction system greatly improved the safety and make the reaction easy to scale up.
2019, 30(5): 1055-1058
doi: 10.1016/j.cclet.2019.02.016
Abstract:
Using 2-vinylnaphthalene, aza-BODIPYs with the naphthyl groups at 1, 7-positions were prepared and their photophysical properties were characterized. Due to attachment of the naphthyl groups at 1, 7-positions, aza-BODIPYs show long-wavelength absorption and emission in the near-infrared region. The singlet oxygen generation of the dibromo substituted aza-BODIPY with the naphthyl groups at 1, 7-positions as a photosensitizer was more effective than that of the corresponding aza-BODIPY with the phenyl groups at 1, 7-positions. No photobleaching of the naphthyl-containing aza-BODIPY was observed and such NIR aza-BODIPY could be used for the singlet oxygen generation.
Using 2-vinylnaphthalene, aza-BODIPYs with the naphthyl groups at 1, 7-positions were prepared and their photophysical properties were characterized. Due to attachment of the naphthyl groups at 1, 7-positions, aza-BODIPYs show long-wavelength absorption and emission in the near-infrared region. The singlet oxygen generation of the dibromo substituted aza-BODIPY with the naphthyl groups at 1, 7-positions as a photosensitizer was more effective than that of the corresponding aza-BODIPY with the phenyl groups at 1, 7-positions. No photobleaching of the naphthyl-containing aza-BODIPY was observed and such NIR aza-BODIPY could be used for the singlet oxygen generation.
2019, 30(5): 1059-1062
doi: 10.1016/j.cclet.2019.01.013
Abstract:
A highly efficient coupling reaction of N-heterocyclic carbene precursors with sulfonyl azides has been developed, affording a variety of pyrido[1, 2-c][1, 2, 4]triazole-based π-conjugated triazenes. The present reaction proceeds under very mild conditions with good functional group tolerance. The resulting triazenes exhibit selective and sensitive fluorescent response toward Fe3+ ion.
A highly efficient coupling reaction of N-heterocyclic carbene precursors with sulfonyl azides has been developed, affording a variety of pyrido[1, 2-c][1, 2, 4]triazole-based π-conjugated triazenes. The present reaction proceeds under very mild conditions with good functional group tolerance. The resulting triazenes exhibit selective and sensitive fluorescent response toward Fe3+ ion.
2019, 30(5): 1063-1066
doi: 10.1016/j.cclet.2019.03.017
Abstract:
Pyridine-Si-xanthene, a novel near-infrared fluorescent dye, dispalys better photophysical properties compared with Si-rhodamines including improved modifiability and red-shifted emission wavelength. The application is exemplified through the development of a lysosomes-targeting probe capable of imaging cysteine in cells and in vivo.
Pyridine-Si-xanthene, a novel near-infrared fluorescent dye, dispalys better photophysical properties compared with Si-rhodamines including improved modifiability and red-shifted emission wavelength. The application is exemplified through the development of a lysosomes-targeting probe capable of imaging cysteine in cells and in vivo.
2019, 30(5): 1067-1070
doi: 10.1016/j.cclet.2019.01.020
Abstract:
Förster resonance energy transfer (FRET) is a widely used distance measurement method to illustrate protein conformational dynamics. The FRET method relies on the distance between donor and acceptor, as well as the labelling efficiency, the size and the properties of the fluorophores. Here, we labelled a pair of small fluorophores and calculated the energy transferred efficiency through fluorescence lifetime analysis, which can provide more reliable distance measurement than intensity attenuation. The donor fluorophore, 7-hydroxycoumarin-4-yl-ethylglycine (HC), was genetically incorporated into specific sites of PYL10, obtaining complete labelling efficiency. The acceptor fluorophore, Alexa488, was labelled through the disulfide bond, whose labelling efficiency was estimated through both absorption peaks and lifetime populations. Fluorescence lifetime and anisotropy analysis showed ABA-induced local conformation changes and dynamics of several HC incorporation sites of PYL10. The lifetime-based FRET distance measurement illustrated the conformation changes of PYL10 with or without ABA application, which is consistent with the previously reported crystal structures.
Förster resonance energy transfer (FRET) is a widely used distance measurement method to illustrate protein conformational dynamics. The FRET method relies on the distance between donor and acceptor, as well as the labelling efficiency, the size and the properties of the fluorophores. Here, we labelled a pair of small fluorophores and calculated the energy transferred efficiency through fluorescence lifetime analysis, which can provide more reliable distance measurement than intensity attenuation. The donor fluorophore, 7-hydroxycoumarin-4-yl-ethylglycine (HC), was genetically incorporated into specific sites of PYL10, obtaining complete labelling efficiency. The acceptor fluorophore, Alexa488, was labelled through the disulfide bond, whose labelling efficiency was estimated through both absorption peaks and lifetime populations. Fluorescence lifetime and anisotropy analysis showed ABA-induced local conformation changes and dynamics of several HC incorporation sites of PYL10. The lifetime-based FRET distance measurement illustrated the conformation changes of PYL10 with or without ABA application, which is consistent with the previously reported crystal structures.
2019, 30(5): 1071-1074
doi: 10.1016/j.cclet.2018.12.031
Abstract:
Two fluorescent "off-on" probes YYH1 and YYH2 were used for the detection of mitochondrial polarity and viscosity. Both probes have two emission bands: The peak of shorter wavelength was sensitive to the polarity, while that in longer wavelength region was sensitive to the viscosity, which enables us to detect medium polarity and viscosity simultaneously. The lg(Ishort/Ilong) of YYH1 exhibited linear relationship to the solvent polarity, while that of YYH2 was closely related to the solvent viscosity. Furthermore, both probes showed potential in bioimaging mitochondrial polarity or viscosity in living cells.
Two fluorescent "off-on" probes YYH1 and YYH2 were used for the detection of mitochondrial polarity and viscosity. Both probes have two emission bands: The peak of shorter wavelength was sensitive to the polarity, while that in longer wavelength region was sensitive to the viscosity, which enables us to detect medium polarity and viscosity simultaneously. The lg(Ishort/Ilong) of YYH1 exhibited linear relationship to the solvent polarity, while that of YYH2 was closely related to the solvent viscosity. Furthermore, both probes showed potential in bioimaging mitochondrial polarity or viscosity in living cells.
2019, 30(5): 1075-1077
doi: 10.1016/j.cclet.2019.02.008
Abstract:
A ratiometric fluorescence probe, NClO, for the rapid and selective detection of HClO had been designed and synthesized based on a 1, 8-naphthalimide derivative. Probe NClO displayed a red emission (λmax=615 nm). In the presence of HClO, the solution of probe NClO gave off a strong green fluorescence (λem, max=520 nm) with a rapid response (within seconds). This probe had been applied to image HClO in living cells and zebra fish.
A ratiometric fluorescence probe, NClO, for the rapid and selective detection of HClO had been designed and synthesized based on a 1, 8-naphthalimide derivative. Probe NClO displayed a red emission (λmax=615 nm). In the presence of HClO, the solution of probe NClO gave off a strong green fluorescence (λem, max=520 nm) with a rapid response (within seconds). This probe had been applied to image HClO in living cells and zebra fish.
2019, 30(5): 1078-1082
doi: 10.1016/j.cclet.2018.10.017
Abstract:
Fluorescent organic nanoparticles (NPs) based on aggregation-induced emission (AIE)-active molecules, are widely applied as non-invasive tools in bio-imaging and demonstrate great potential for studying physiological and pathological processes. In this paper, we report the synthesis of highly emissive AIEgen-based NPs (SCA NPs) via reprecipitation without any carriers as long-term cell trackers. Uniformly sized SCA NPs enjoy the advantages of high brightness, good stability, large Stokes shift, good biocompatibility, and high photostability. The SCA NPs were successfully applied for in vitro bio-imaging of HeLa cells with an excellent cancer cell uptake. In addition, a strong fluorescence from SCA NPs can still be clearly observed in HeLa cells after incubation for six generations over 15 days. Thus, the SCA NPs could be ideal fluorescent probes for non-invasive long-term cellular imaging. The AIE-active NPs display superior performance and provide a basis for the development of fluorescent organic probes for monitoring biological processes.
Fluorescent organic nanoparticles (NPs) based on aggregation-induced emission (AIE)-active molecules, are widely applied as non-invasive tools in bio-imaging and demonstrate great potential for studying physiological and pathological processes. In this paper, we report the synthesis of highly emissive AIEgen-based NPs (SCA NPs) via reprecipitation without any carriers as long-term cell trackers. Uniformly sized SCA NPs enjoy the advantages of high brightness, good stability, large Stokes shift, good biocompatibility, and high photostability. The SCA NPs were successfully applied for in vitro bio-imaging of HeLa cells with an excellent cancer cell uptake. In addition, a strong fluorescence from SCA NPs can still be clearly observed in HeLa cells after incubation for six generations over 15 days. Thus, the SCA NPs could be ideal fluorescent probes for non-invasive long-term cellular imaging. The AIE-active NPs display superior performance and provide a basis for the development of fluorescent organic probes for monitoring biological processes.
2019, 30(5): 1083-1088
doi: 10.1016/j.cclet.2019.01.003
Abstract:
We synthesized PEG-TPP as carrier to encapsulate paclitaxel (PTX) in the form of micelles to overcome its water-solubility problem. PTX-loaded micelles possess a-week stability and appropriate particle size (152.1±1.2 nm) which is beneficial for enhanced permeability and retention (EPR) effect. Strong pH dependence of PTX releasing from micelles is verified by in vitro release study. At cellular level, PTX-loaded micelles can target mitochondria effectively which may results a better cytotoxicity of micelles (especially IC50=0.123±0.035 μmol/L of micelles and 0.298±0.067 μmol/L of PTX alone on MCF-7 cells). The fluorescence distributions of both isolated and sliced organs show that the micelles can effectively target tumors. Moreover, we further prove the enhanced therapeutic effects of micelles in tumor-bearing mice comparing with PTX alone. The results show that the biodegradable drug delivery system prepared by PEG-TPP can overcome the poor solubility of paclitaxel and improve its tumor targeting and antitumor activity.
We synthesized PEG-TPP as carrier to encapsulate paclitaxel (PTX) in the form of micelles to overcome its water-solubility problem. PTX-loaded micelles possess a-week stability and appropriate particle size (152.1±1.2 nm) which is beneficial for enhanced permeability and retention (EPR) effect. Strong pH dependence of PTX releasing from micelles is verified by in vitro release study. At cellular level, PTX-loaded micelles can target mitochondria effectively which may results a better cytotoxicity of micelles (especially IC50=0.123±0.035 μmol/L of micelles and 0.298±0.067 μmol/L of PTX alone on MCF-7 cells). The fluorescence distributions of both isolated and sliced organs show that the micelles can effectively target tumors. Moreover, we further prove the enhanced therapeutic effects of micelles in tumor-bearing mice comparing with PTX alone. The results show that the biodegradable drug delivery system prepared by PEG-TPP can overcome the poor solubility of paclitaxel and improve its tumor targeting and antitumor activity.
2019, 30(5): 1089-1092
doi: 10.1016/j.cclet.2019.01.022
Abstract:
Herein, we demonstrate that silica films with perpendicular macroporous channels and accessible ordered mesopores can be conveniently prepared. The hierarchical macroporous-mesoporous silica films are synthesized by using zinc oxide nanorod array as macroporous template and CTAB surfactant as mesoporous template. In basic surfactant-containing solution, ordered mesoporous silica shells homogeneously grow on the zinc oxide nanorod array. The growth of the mesostructures do not require any chemical modification for the zinc oxide nanorod, which opens a new way for preparing hierarchical silica films with perpendicular mesochannels. The prepared hierarchical macroporous- mesoporous silica films possess a uniform thickness of 2 μm, large perpendicular macropores with a length of 1.8 μm and a width of 80 nm, and accessible ordered mesopores. Separation experiment demonstrates that this macroporous-mesoporous film can effectively separate biomolecules with different sizes.
Herein, we demonstrate that silica films with perpendicular macroporous channels and accessible ordered mesopores can be conveniently prepared. The hierarchical macroporous-mesoporous silica films are synthesized by using zinc oxide nanorod array as macroporous template and CTAB surfactant as mesoporous template. In basic surfactant-containing solution, ordered mesoporous silica shells homogeneously grow on the zinc oxide nanorod array. The growth of the mesostructures do not require any chemical modification for the zinc oxide nanorod, which opens a new way for preparing hierarchical silica films with perpendicular mesochannels. The prepared hierarchical macroporous- mesoporous silica films possess a uniform thickness of 2 μm, large perpendicular macropores with a length of 1.8 μm and a width of 80 nm, and accessible ordered mesopores. Separation experiment demonstrates that this macroporous-mesoporous film can effectively separate biomolecules with different sizes.
2019, 30(5): 957-960
doi: 10.1016/j.cclet.2019.01.018
Abstract:
A symmetric pillararene-based receptor containing ten triazole units was synthesized. Interestingly, it formed 1:1 complexes instead of 1:2 with different halide anions. This was caused by the cooperative multivalent hydrogen-bond interactions between the triazole protons on one side of the receptor and the halide anion, which changed its structure from pillar to conical. However, by the regulation of the effector F-, it can work like an excavator grapple selectively grasps a PF6- anion.
A symmetric pillararene-based receptor containing ten triazole units was synthesized. Interestingly, it formed 1:1 complexes instead of 1:2 with different halide anions. This was caused by the cooperative multivalent hydrogen-bond interactions between the triazole protons on one side of the receptor and the halide anion, which changed its structure from pillar to conical. However, by the regulation of the effector F-, it can work like an excavator grapple selectively grasps a PF6- anion.
2019, 30(5): 977-980
doi: 10.1016/j.cclet.2019.01.023
Abstract:
Insect chitinolytic β-N-acetyl-D-hexosaminidase, such as OfHex1 from Ostrinia furnacalis, is a potential target for insecticide design. Among the known OfHex1 inhibitors, Q2 is of great interest because it is the first non-carbohydrate inhibitor. In this study, we designed and synthesized a series of Q2 derivatives by replacing the thiadiazole and naphthalimide groups and changing the linker length. Compound 3m showed the best inhibitory activity with a Ki value of 0.34 μmol/L against OfHex1, which is about onequarter that of Q2 (Ki=1.4 μmol/L). Compound 6a showed the best inhibitory activity among the quinoline-containing derivatives (Ki=2.3 μmol/L). Molecular docking indicated that although 3m, 6a, and Q2 binding the active pocket of OfHex1 in similar mode, compound 3m engaged better than the other compounds in intermolecular interaction with OfHex1.
Insect chitinolytic β-N-acetyl-D-hexosaminidase, such as OfHex1 from Ostrinia furnacalis, is a potential target for insecticide design. Among the known OfHex1 inhibitors, Q2 is of great interest because it is the first non-carbohydrate inhibitor. In this study, we designed and synthesized a series of Q2 derivatives by replacing the thiadiazole and naphthalimide groups and changing the linker length. Compound 3m showed the best inhibitory activity with a Ki value of 0.34 μmol/L against OfHex1, which is about onequarter that of Q2 (Ki=1.4 μmol/L). Compound 6a showed the best inhibitory activity among the quinoline-containing derivatives (Ki=2.3 μmol/L). Molecular docking indicated that although 3m, 6a, and Q2 binding the active pocket of OfHex1 in similar mode, compound 3m engaged better than the other compounds in intermolecular interaction with OfHex1.
2019, 30(5): 981-984
doi: 10.1016/j.cclet.2019.01.034
Abstract:
Pafuranones A (1) and B (2), a pair of new epimeric polyketide dimers, were isolated from the fungus Paraconiothyrium sp. OUCMDZ-3316 associated with the marine algae Enteromorpha prolifera. Their structures, including absolute configurations, were fully elucidated based on spectroscopic analysis, calculated ECD, and chemical methods. Pafuranones A (1) and B (2) possess a rare dimeric furanone skeleton, which might be formed through a conjugate addition of the monomeric units followed by an intramolecular cyclization.
Pafuranones A (1) and B (2), a pair of new epimeric polyketide dimers, were isolated from the fungus Paraconiothyrium sp. OUCMDZ-3316 associated with the marine algae Enteromorpha prolifera. Their structures, including absolute configurations, were fully elucidated based on spectroscopic analysis, calculated ECD, and chemical methods. Pafuranones A (1) and B (2) possess a rare dimeric furanone skeleton, which might be formed through a conjugate addition of the monomeric units followed by an intramolecular cyclization.
2019, 30(5): 985-988
doi: 10.1016/j.cclet.2019.01.017
Abstract:
Photodeposition emerges as a convenient method to synthesize metal particles on semiconductor supports. In this work, we study the photodeposition of Pt on Cu2O-TiO2 composite surfaces employing H2PtCl6 aqueous solution as the precursor and reveal a key role of isoelectric point of oxide surfaces on the Pt photodeposition process. Under the photodeposition conditions, Pt metal particles are facilely photodeposited on TiO2 support; on Cu2O-TiO2 composite supports, the Cu2O surface is positively charged and enriched with photo-excited holes while the TiO2 surface is negatively charged and enriched with photo-excited electrons. This lead to the preferential adsorption of PtCl62- anion precursor on the Cu2O surface of Cu2O-TiO2 composite and the dominant formation of Pt oxide particles on Cu2O surface but few Pt metal particles on TiO2 surface. Consequently, the activity of resulting Pt/Cu2O-TiO2 composite photocatalysts in photocatalytic water reduction decreases as the Cu2O content increases. These results deepen the understanding of photodeposition processes on oxide composite surfaces.
Photodeposition emerges as a convenient method to synthesize metal particles on semiconductor supports. In this work, we study the photodeposition of Pt on Cu2O-TiO2 composite surfaces employing H2PtCl6 aqueous solution as the precursor and reveal a key role of isoelectric point of oxide surfaces on the Pt photodeposition process. Under the photodeposition conditions, Pt metal particles are facilely photodeposited on TiO2 support; on Cu2O-TiO2 composite supports, the Cu2O surface is positively charged and enriched with photo-excited holes while the TiO2 surface is negatively charged and enriched with photo-excited electrons. This lead to the preferential adsorption of PtCl62- anion precursor on the Cu2O surface of Cu2O-TiO2 composite and the dominant formation of Pt oxide particles on Cu2O surface but few Pt metal particles on TiO2 surface. Consequently, the activity of resulting Pt/Cu2O-TiO2 composite photocatalysts in photocatalytic water reduction decreases as the Cu2O content increases. These results deepen the understanding of photodeposition processes on oxide composite surfaces.
2019, 30(5): 989-994
doi: 10.1016/j.cclet.2019.02.021
Abstract:
The development of high-efficiency, earth-abundant, and durable oxygen reduction reaction (ORR) electrocatalysts is desirable for commercialization of fuel cells, but remains a great challenge. Herein, we develop a facile and practical method for preparing efficient ORR electrocatalysts by directly growing metal-organic frameworks (MOFs) Co2(INA)4·DMF (HINA=isonicotinic acid, 1) and {[Co2(TPI) (H2O)2(OH)]·DMF} (H3TPI=5-(4-(tetrazol-5-yl) phenyl) isophthalic acid, 2) on the commercial carbon (CC). The resulting MOF/CCs were further pyrolysis to functionalize CC by trace amount of cobalt oxides, resulting in two composites Cal-MOF-1/CC (3) and Cal-MOF-2/CC (4), which can be used as efficient electrocatalysts for ORR with remarkable stability and large diffusion-limited current density, even superior to that of commercial Pt/C catalysts. Detail study reveals that the linking ligands with different structure and nitrogen contents in 1 and 2 smartly influence the types of cobalt oxides. The catalytic activity of Co3O4/CoO/Co co-doped CC in 4 was much enhanced compared to that of CoO-doped CC in 3.
The development of high-efficiency, earth-abundant, and durable oxygen reduction reaction (ORR) electrocatalysts is desirable for commercialization of fuel cells, but remains a great challenge. Herein, we develop a facile and practical method for preparing efficient ORR electrocatalysts by directly growing metal-organic frameworks (MOFs) Co2(INA)4·DMF (HINA=isonicotinic acid, 1) and {[Co2(TPI) (H2O)2(OH)]·DMF} (H3TPI=5-(4-(tetrazol-5-yl) phenyl) isophthalic acid, 2) on the commercial carbon (CC). The resulting MOF/CCs were further pyrolysis to functionalize CC by trace amount of cobalt oxides, resulting in two composites Cal-MOF-1/CC (3) and Cal-MOF-2/CC (4), which can be used as efficient electrocatalysts for ORR with remarkable stability and large diffusion-limited current density, even superior to that of commercial Pt/C catalysts. Detail study reveals that the linking ligands with different structure and nitrogen contents in 1 and 2 smartly influence the types of cobalt oxides. The catalytic activity of Co3O4/CoO/Co co-doped CC in 4 was much enhanced compared to that of CoO-doped CC in 3.
2019, 30(5): 995-999
doi: 10.1016/j.cclet.2019.01.028
Abstract:
The composition ratio of donor and acceptor materials in organic bulk heterojunction (BHJ) is one of the key parameters to govern the performance in organic solar cells (OSCs). Therefore, high-performance non-fullerene organic bulk heterojunction consisting of poly[(2, 6-(4, 8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1, 2-b:4, 5-b']dithiophene))-co-(1, 3-di(5-thiophene-2-yl)-5, 7-bis(2-ethylhexyl) benzo[1, 2-c:4, 5-c']dithiophene-4, 8-dione)] (PBDB-T) and 3, 9-bis(2-methylene-(3-(1, 1-dicyanomethylene)-indanone))-5, 5, 11, 11-tetrakis(4-hexylphenyl)-dithieno[2, 3-d:2', 3'-d']-s-indaceno[1, 2-b:5, 6-b']-dithiophene (ITIC) are used to investigate the correlation among various donor: acceptor (D:A) ratios, photophysical properties and photovoltaic performance. Interestingly, the function of short-circuit current (Jsc) and D:A ratios demonstrates an axisymmetric trend. When the blending ratio of D:A deviates from the optimal ratio, the symmetrically decreased Jsc is derived from a reduction in the D:A interface or amorphous region. Research on the steady-state photoluminescence (PL), the time-resolved fluorescence spectroscopy measurements, atomic force microscopic (AFM) and grazing-incidence small angle X-rays scattering (GIWAXS) indicates no significant variation in energy loss in the process of changing D:A ratios in BHJs. With high donor or acceptor content, the domain size improves significantly, but the distance of π-π stacking corresponding to molecular packing has not changed significantly, and the bi-continuous percolation pathways were not obviously influenced.
The composition ratio of donor and acceptor materials in organic bulk heterojunction (BHJ) is one of the key parameters to govern the performance in organic solar cells (OSCs). Therefore, high-performance non-fullerene organic bulk heterojunction consisting of poly[(2, 6-(4, 8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1, 2-b:4, 5-b']dithiophene))-co-(1, 3-di(5-thiophene-2-yl)-5, 7-bis(2-ethylhexyl) benzo[1, 2-c:4, 5-c']dithiophene-4, 8-dione)] (PBDB-T) and 3, 9-bis(2-methylene-(3-(1, 1-dicyanomethylene)-indanone))-5, 5, 11, 11-tetrakis(4-hexylphenyl)-dithieno[2, 3-d:2', 3'-d']-s-indaceno[1, 2-b:5, 6-b']-dithiophene (ITIC) are used to investigate the correlation among various donor: acceptor (D:A) ratios, photophysical properties and photovoltaic performance. Interestingly, the function of short-circuit current (Jsc) and D:A ratios demonstrates an axisymmetric trend. When the blending ratio of D:A deviates from the optimal ratio, the symmetrically decreased Jsc is derived from a reduction in the D:A interface or amorphous region. Research on the steady-state photoluminescence (PL), the time-resolved fluorescence spectroscopy measurements, atomic force microscopic (AFM) and grazing-incidence small angle X-rays scattering (GIWAXS) indicates no significant variation in energy loss in the process of changing D:A ratios in BHJs. With high donor or acceptor content, the domain size improves significantly, but the distance of π-π stacking corresponding to molecular packing has not changed significantly, and the bi-continuous percolation pathways were not obviously influenced.
2019, 30(5): 1000-1004
doi: 10.1016/j.cclet.2018.12.019
Abstract:
Developing oxygen-free methodology for the conversion of alcohols to carbonyls is essentially important because it suppresses the over-oxidation of alcohols to carboxylic acids and enables the production of energetic hydrogen. Here we report a finding of feasible oxidant-free dehydrogenation of glycerol over chemically-pure Au clusters synthesized by a green chemistry method named as laser ablation in liquid (LAL). As results, glycerol is dehydrogenated to form glyceraldehyde which undergoes subsequent dehydrogenation to hydroxymethyl glyoxal. For this, reaction dynamics calculations find interesting dehydrogenation reaction pathways with a low-energy barrier of transition state initiated by hydrogen atom transfer from methene, which differs from the general reaction mechanism based on hydroxyl. Furthermore, it is interesting that the presence of additional -OH group molecules especially H2O can effectively lower the energy barrier in the activation of the O-H and C-H bonds in glycerol. This principle is also applicable to the oxidant-free dehydrogenation of methanol and ethanol, helping to fully understand the catalytic mechanism of alcohols conversion chemistry.
Developing oxygen-free methodology for the conversion of alcohols to carbonyls is essentially important because it suppresses the over-oxidation of alcohols to carboxylic acids and enables the production of energetic hydrogen. Here we report a finding of feasible oxidant-free dehydrogenation of glycerol over chemically-pure Au clusters synthesized by a green chemistry method named as laser ablation in liquid (LAL). As results, glycerol is dehydrogenated to form glyceraldehyde which undergoes subsequent dehydrogenation to hydroxymethyl glyoxal. For this, reaction dynamics calculations find interesting dehydrogenation reaction pathways with a low-energy barrier of transition state initiated by hydrogen atom transfer from methene, which differs from the general reaction mechanism based on hydroxyl. Furthermore, it is interesting that the presence of additional -OH group molecules especially H2O can effectively lower the energy barrier in the activation of the O-H and C-H bonds in glycerol. This principle is also applicable to the oxidant-free dehydrogenation of methanol and ethanol, helping to fully understand the catalytic mechanism of alcohols conversion chemistry.
2019, 30(5): 1005-1008
doi: 10.1016/j.cclet.2019.01.032
Abstract:
In this text, we use inexpensive and natural amino acid, successfully obtained the asymmetric crystallization of three PTCs, [Ti6(OiPr)14(μ2-O)(μ3-O)2(D/L-pGlu)2] (D-PTC-53; L-PTC-53; H2pGlu=pyroglutamic acid) and [Ti6(OiPr)14(μ2-O)(μ3-O)2(D-pGlu)2][Ti6(OiPr)14(μ2-O)(μ3-O)2(L-pGlu)2] (D, L-PTC-53). Interestingly, in situ lactamide reaction starting from glutamic acid to pyroglutamic acid was observed. In addition, the chirality features of these PTCs have been thoroughly discussed. The two enantiomers crystallize in chiral P21 space group. The optically pure pGlu ligands transform its chirality to the inorganic titanium oxo clusters. As a result, the stack of these inorganic clusters generates homochiral helical chains along the characteristic axial direction. Apart from the microscopic structural analysis, the macroscopic solid-state samples exhibit unusual strong circular dichroism (CD) signals, further verified the homochiral feature of the enantiomers.
In this text, we use inexpensive and natural amino acid, successfully obtained the asymmetric crystallization of three PTCs, [Ti6(OiPr)14(μ2-O)(μ3-O)2(D/L-pGlu)2] (D-PTC-53; L-PTC-53; H2pGlu=pyroglutamic acid) and [Ti6(OiPr)14(μ2-O)(μ3-O)2(D-pGlu)2][Ti6(OiPr)14(μ2-O)(μ3-O)2(L-pGlu)2] (D, L-PTC-53). Interestingly, in situ lactamide reaction starting from glutamic acid to pyroglutamic acid was observed. In addition, the chirality features of these PTCs have been thoroughly discussed. The two enantiomers crystallize in chiral P21 space group. The optically pure pGlu ligands transform its chirality to the inorganic titanium oxo clusters. As a result, the stack of these inorganic clusters generates homochiral helical chains along the characteristic axial direction. Apart from the microscopic structural analysis, the macroscopic solid-state samples exhibit unusual strong circular dichroism (CD) signals, further verified the homochiral feature of the enantiomers.
2019, 30(5): 1009-1012
doi: 10.1016/j.cclet.2018.12.021
Abstract:
Construction of multi-enzyme complexes not only can help expand the understanding of biological mechanisms, but also holds great promise in biosynthesis, biosensing and biomedicine. Herein, a hybrid multi-enzyme system, CeO2/glucose oxidase (GOx) nanocomplex was developed via self-assembly and exhibited excellent catalytic activity toward cascade reactions. Compared to mixed GOx and CeO2, the nanocomplexes displayed enhanced efficiency, mainly attributed to the minimal diffusion of intermediate in the nanocomplexes system. Moreover, the nanocomplexes exhibited outstanding long-term stability and excellent recyclability. Benefiting from these merits, a highly sensitive and selective biosensor for colorimetric detection of glucose was constructed based on CeO2/GOx nanocomplexes. Such a self-assembled nanozyme complex offers a simple and efficient example to build spatially confined multi-enzyme systems to potentiate their applications in energy conversion, detoxification and bioanalysis
Construction of multi-enzyme complexes not only can help expand the understanding of biological mechanisms, but also holds great promise in biosynthesis, biosensing and biomedicine. Herein, a hybrid multi-enzyme system, CeO2/glucose oxidase (GOx) nanocomplex was developed via self-assembly and exhibited excellent catalytic activity toward cascade reactions. Compared to mixed GOx and CeO2, the nanocomplexes displayed enhanced efficiency, mainly attributed to the minimal diffusion of intermediate in the nanocomplexes system. Moreover, the nanocomplexes exhibited outstanding long-term stability and excellent recyclability. Benefiting from these merits, a highly sensitive and selective biosensor for colorimetric detection of glucose was constructed based on CeO2/GOx nanocomplexes. Such a self-assembled nanozyme complex offers a simple and efficient example to build spatially confined multi-enzyme systems to potentiate their applications in energy conversion, detoxification and bioanalysis
2019, 30(5): 1013-1016
doi: 10.1016/j.cclet.2018.12.022
Abstract:
High sensitive, accurate detection for tumor-associated overexpressed enzyme activity is highly significant for further understanding enzyme function, discovering potential drugs, and early diagnosis and prevention of diseases. In this work, we developed a facile, direct and single-step detection platform for primary ovarian cancers related glycosidase activity based on the inner filter effect (IFE) between glycosidase catalytic product and black phosphorus quantum dots (BPQDs). Highly fluorescent BPQDs were successfully synthesized from bulk black phosphorus by a simple liquid exfoliation method. Under the catalysis of β-galactosidase, p-nitrophenyl-β-D-galactopyranoside (PNPG) was transformed into pnitrophenol (PNP) and β-D-galactopyranoside. Meanwhile, the absorption of catalytic product PNP greatly overlapped with the excitation and emission spectra of fluorescent BPQDs, leading to the fluorescence quenching of BPQDs with a high quenching efficiency. The proposed sensing strategy provided a low detection limit of 0.76 U/L, which was 1-2 orders of magnitude lower than most unmodified sensing platforms. D-Galactal was selected as the inhibitor for β-galactosidase to further assess the feasibility of screening potential inhibitors. The fluorescence recovery of BPQDs suggests that the unmodified sensing platform is feasible to discover potential drugs of β-galactosidase. Our work paves a general way in the detection of glycosidase activity with fluorescent BPQDs, which can be promising for glycosidase-related disease diagnosis and pathophysiology elucidation.
High sensitive, accurate detection for tumor-associated overexpressed enzyme activity is highly significant for further understanding enzyme function, discovering potential drugs, and early diagnosis and prevention of diseases. In this work, we developed a facile, direct and single-step detection platform for primary ovarian cancers related glycosidase activity based on the inner filter effect (IFE) between glycosidase catalytic product and black phosphorus quantum dots (BPQDs). Highly fluorescent BPQDs were successfully synthesized from bulk black phosphorus by a simple liquid exfoliation method. Under the catalysis of β-galactosidase, p-nitrophenyl-β-D-galactopyranoside (PNPG) was transformed into pnitrophenol (PNP) and β-D-galactopyranoside. Meanwhile, the absorption of catalytic product PNP greatly overlapped with the excitation and emission spectra of fluorescent BPQDs, leading to the fluorescence quenching of BPQDs with a high quenching efficiency. The proposed sensing strategy provided a low detection limit of 0.76 U/L, which was 1-2 orders of magnitude lower than most unmodified sensing platforms. D-Galactal was selected as the inhibitor for β-galactosidase to further assess the feasibility of screening potential inhibitors. The fluorescence recovery of BPQDs suggests that the unmodified sensing platform is feasible to discover potential drugs of β-galactosidase. Our work paves a general way in the detection of glycosidase activity with fluorescent BPQDs, which can be promising for glycosidase-related disease diagnosis and pathophysiology elucidation.
2019, 30(5): 1017-1020
doi: 10.1016/j.cclet.2019.01.029
Abstract:
Aflatoxin B1 (AFB1) is a highly toxic mycotoxin, and rapid and sensitive detection of AFB1 is in demand for food safety and environmental analysis. Here we described a simple aptamer molecular beacon assay for rapid detection of aflatoxin B1 (AFB1) by using an aptamer with a fluorescein (FAM) label at the 5' end and a fluorescence quencher (black hole quencher 1, BHQ1) at the 30 end. In the presence of AFB1, the aptamer probe bound with AFB1 and induced a hairpin structure, drawing FAM and BHQ1 into close proximity and leading to fluorescence quenching. This assay allowed for a detection limit of 3.9 nmol/L and a dynamic range from 3.9 nmol/L to 4 μmol/L. Specificity test showed other mycotoxins including ochratoxin A, ochratoxin B, fumonisin B1, fumonisin B2, and zearalenone had negligible influence on detection of AFB1. AFB1 spiked in diluted liquor wine, methanol, or corn flour samples was successfully detected by using this aptamer probe, and the assay showed potential for real sample analysis.
Aflatoxin B1 (AFB1) is a highly toxic mycotoxin, and rapid and sensitive detection of AFB1 is in demand for food safety and environmental analysis. Here we described a simple aptamer molecular beacon assay for rapid detection of aflatoxin B1 (AFB1) by using an aptamer with a fluorescein (FAM) label at the 5' end and a fluorescence quencher (black hole quencher 1, BHQ1) at the 30 end. In the presence of AFB1, the aptamer probe bound with AFB1 and induced a hairpin structure, drawing FAM and BHQ1 into close proximity and leading to fluorescence quenching. This assay allowed for a detection limit of 3.9 nmol/L and a dynamic range from 3.9 nmol/L to 4 μmol/L. Specificity test showed other mycotoxins including ochratoxin A, ochratoxin B, fumonisin B1, fumonisin B2, and zearalenone had negligible influence on detection of AFB1. AFB1 spiked in diluted liquor wine, methanol, or corn flour samples was successfully detected by using this aptamer probe, and the assay showed potential for real sample analysis.
2019, 30(5): 1021-1023
doi: 10.1016/j.cclet.2018.12.028
Abstract:
Using cesium lead halide perovskite nanocrystals, CsPb(Cl/Br)3, as a light absorber, we report a highly effective UV and blue light blocking film. The CsPb(Cl/Br)3 nanocrystals are well dispersed in the ethyl cellulose (EC) matrix to compose a UV and blue light shielding film, and the absorption edge of the film is tunable by adjusting Cl to Br ratio using anion exchange. The CsPbCl2Br-EC film exhibits a transmittance of 5% at 459 nm, 90% at 478 nm and 95% in the range of 500-800 nm, which makes it excellent for UV and blue light shielding. In addition, the as-prepared EC-CsPb(Cl/Br)3 film shows excellent photostability under UV irradiation. Results demonstrate that this EC-CsPb(Cl/Br)3 based materials with sharp absorbance edges, tunable blocking wavelength, and high photostability can be useful for the applications in UV and blue light blocking and optical filters
Using cesium lead halide perovskite nanocrystals, CsPb(Cl/Br)3, as a light absorber, we report a highly effective UV and blue light blocking film. The CsPb(Cl/Br)3 nanocrystals are well dispersed in the ethyl cellulose (EC) matrix to compose a UV and blue light shielding film, and the absorption edge of the film is tunable by adjusting Cl to Br ratio using anion exchange. The CsPbCl2Br-EC film exhibits a transmittance of 5% at 459 nm, 90% at 478 nm and 95% in the range of 500-800 nm, which makes it excellent for UV and blue light shielding. In addition, the as-prepared EC-CsPb(Cl/Br)3 film shows excellent photostability under UV irradiation. Results demonstrate that this EC-CsPb(Cl/Br)3 based materials with sharp absorbance edges, tunable blocking wavelength, and high photostability can be useful for the applications in UV and blue light blocking and optical filters
2019, 30(5): 1024-1026
doi: 10.1016/j.cclet.2019.01.005
Abstract:
A method for quantitative determination of fish sperm deoxyribonucleic acid (fsDNA) was developed by using titanium dioxide (TiO2) as an adsorbent and near-infrared diffuse reflectance spectroscopy (NIRDRS). The selective enrichment of fsDNA was proved by comparing the adsorption efficiency of bovine serum albumin, tyrosine and tryptophan, and the low adsorption background of TiO2 was illustrated by comparing the spectra of four commonly-used inorganic adsorbents (alkaline aluminium oxide, neutral aluminium oxide, nano-hydroxyapatite and silica). The spectral feature of fsDNA can be clearly observed in the spectrum of the sample. Partial least squares (PLS) model was built for quantitative determination of fsDNA using 28 solutions, and 13 solutions with interferences were used for validation of the model. The results showed that the correlation coefficient (R) between the predicted and the reference concentration is 0.9727 and the recoveries of the validation samples are in the range of 98.2%-100.7%
A method for quantitative determination of fish sperm deoxyribonucleic acid (fsDNA) was developed by using titanium dioxide (TiO2) as an adsorbent and near-infrared diffuse reflectance spectroscopy (NIRDRS). The selective enrichment of fsDNA was proved by comparing the adsorption efficiency of bovine serum albumin, tyrosine and tryptophan, and the low adsorption background of TiO2 was illustrated by comparing the spectra of four commonly-used inorganic adsorbents (alkaline aluminium oxide, neutral aluminium oxide, nano-hydroxyapatite and silica). The spectral feature of fsDNA can be clearly observed in the spectrum of the sample. Partial least squares (PLS) model was built for quantitative determination of fsDNA using 28 solutions, and 13 solutions with interferences were used for validation of the model. The results showed that the correlation coefficient (R) between the predicted and the reference concentration is 0.9727 and the recoveries of the validation samples are in the range of 98.2%-100.7%
2019, 30(5): 1027-1030
doi: 10.1016/j.cclet.2019.02.004
Abstract:
In this study, a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat, and the SERS detection uses the fresh substrate to avoid the drawback of substrates' short life of use. The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer. The vial is grasped with the palm of the experimenter for several minutes without shaking. The proposed method is simple, rapid, green energy and cost-effective. By adjusting the concentration of trisodium citrate, not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved. As a SERS substrate, the silver colloid has high batch reproducibility and showed good SERS activity. The relative standard deviation between different manufacturers is 5.51% when the substrate of silver colloid is used for the detection of rhodamine 6 G. Using the substrate, the lowest detection concentrations of rhodamine 6 G, crystal violet, enrofloxacin, melamine and leucomalachite green are 1.0×10-8, 6.1×10-8, 1.4×10-6, 7.1×10-5 and 5.1×10-8 mol/L, respectively. Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.
In this study, a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat, and the SERS detection uses the fresh substrate to avoid the drawback of substrates' short life of use. The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer. The vial is grasped with the palm of the experimenter for several minutes without shaking. The proposed method is simple, rapid, green energy and cost-effective. By adjusting the concentration of trisodium citrate, not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved. As a SERS substrate, the silver colloid has high batch reproducibility and showed good SERS activity. The relative standard deviation between different manufacturers is 5.51% when the substrate of silver colloid is used for the detection of rhodamine 6 G. Using the substrate, the lowest detection concentrations of rhodamine 6 G, crystal violet, enrofloxacin, melamine and leucomalachite green are 1.0×10-8, 6.1×10-8, 1.4×10-6, 7.1×10-5 and 5.1×10-8 mol/L, respectively. Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.
2019, 30(5): 1031-1034
doi: 10.1016/j.cclet.2019.03.013
Abstract:
DNA methyltransferase 1 (DNMT1) is a useful biomarker for lung cancer in early clinical diagnosis. A rapid magnetic chemiluminescence immunoassay (MCLIA) for DNMT1 in human serum has been developed. Horseradish peroxidase(HRP)-second-Abwasused to labeled polyclonal antibodies of anti-DNMT1. DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction. In magnetic field, nonspecific materials can be separated. After luminescent substrate luminol-H2O2-BIP was added, the relative light unit (RLU) of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample. The correlative variables involved in the MCLIA valuewere optimized and the methodological evaluationwas carriedout. Afteroptimization, in the range of 0.5-128 ng/mL, the linear regression equation was y=0.5014x + 1.769 (x was logCDNMT1, y was relative luminescence units (RLU)/RLU0), and the limit of detection was 0.01 ng/mL. The RSD of intra- and interassays were 15.8%-16.9% and 14.3%-18.1%, respectively. The recovery was from 70.0% to 106.2%. Furthermore, paralleled with purchasable enzyme-linked immunosorbent assay (ELISA) kits, MCLEIA had lower detection limit, wider linear range and shorter detection time. Therefore, the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.
DNA methyltransferase 1 (DNMT1) is a useful biomarker for lung cancer in early clinical diagnosis. A rapid magnetic chemiluminescence immunoassay (MCLIA) for DNMT1 in human serum has been developed. Horseradish peroxidase(HRP)-second-Abwasused to labeled polyclonal antibodies of anti-DNMT1. DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction. In magnetic field, nonspecific materials can be separated. After luminescent substrate luminol-H2O2-BIP was added, the relative light unit (RLU) of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample. The correlative variables involved in the MCLIA valuewere optimized and the methodological evaluationwas carriedout. Afteroptimization, in the range of 0.5-128 ng/mL, the linear regression equation was y=0.5014x + 1.769 (x was logCDNMT1, y was relative luminescence units (RLU)/RLU0), and the limit of detection was 0.01 ng/mL. The RSD of intra- and interassays were 15.8%-16.9% and 14.3%-18.1%, respectively. The recovery was from 70.0% to 106.2%. Furthermore, paralleled with purchasable enzyme-linked immunosorbent assay (ELISA) kits, MCLEIA had lower detection limit, wider linear range and shorter detection time. Therefore, the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.
2019, 30(5): 1035-1037
doi: 10.1016/j.cclet.2019.01.001
Abstract:
In this study, a point-of-care sensing protocol has been reported for rapid and sensitive detection of Microcystin-LR (MC-LR) in water by personal glucose meter. The proposed immunosensor has been fabricated by using a primary antibody coated ZnFe2O4 nanoparticles to capture the target MC-LR. Consequently, the invertase@secondary antibody-conjugated graphene oxide-Au NPs can be immobilized for formating the sandwich immuno-complexes, which allowed for enzymatic conversion of sucrose to glucose. Thus, the concentration of MC-LR can be refelected by the converted glucose, which can be easily measured by the personal glucose meter (PGM). The PGM readout immunosensing method possessed good reproducibility and stability, which may have significant potential for other applications.
In this study, a point-of-care sensing protocol has been reported for rapid and sensitive detection of Microcystin-LR (MC-LR) in water by personal glucose meter. The proposed immunosensor has been fabricated by using a primary antibody coated ZnFe2O4 nanoparticles to capture the target MC-LR. Consequently, the invertase@secondary antibody-conjugated graphene oxide-Au NPs can be immobilized for formating the sandwich immuno-complexes, which allowed for enzymatic conversion of sucrose to glucose. Thus, the concentration of MC-LR can be refelected by the converted glucose, which can be easily measured by the personal glucose meter (PGM). The PGM readout immunosensing method possessed good reproducibility and stability, which may have significant potential for other applications.
2019, 30(5): 1038-1042
doi: 10.1016/j.cclet.2019.02.017
Abstract:
Cell migration and invasion are critical steps in cancer metastasis, which are the major cause of death in cancer patients. Tumor-associated macrophages (TAMs) and interstitial flow (IF) are two important biochemical and biomechanical cues in tumor microenvironment, play essential roles in tumor progression. However, their combined effects on tumor cell migration and invasion as well as molecular mechanism remains largely unknown. In this work, we developed a microfluidic-based 3D breast cancer model by co-culturing tumor aggregates, macrophages, monocytes and endothelial cells within 3D extracellular matrix in the presence of IF to study tumor cell migration and invasion. On the established platform, we can precisely control the parameters related to tumor microenvironment and observe cellular responses and interactions in real-time. When co-culture of U937 with human umbilical vein endothelial cells (HUVECs) or MDA-MB-231 cells and tri-culture of U937 with HUVECs and MDA-MB-231 cells, we found that mesenchymal-like MDA-MB-231 aggregates activated the monocytes to TAM-like phenotype macrophages. MDA-MB-231 cells and IF simultaneously enhanced the macrophages activation by the stimulation of colony-stimulating factor 1 (CSF-1). The activated macrophages and IF further promoted vascular sprouting via vascular endothelial growth factor (VEGFα) signal and tumor cell invasion. This is the first attempt to study the interaction between macrophages and breast cancer cells under IF condition. Taken together, our results provide a new insight to reveal the important physiological and pathological processes of macrophages-tumor communication. Moreover, our established platform with a more mimetic 3D breast cancer model has the potential for drug screening with more accurate results.
Cell migration and invasion are critical steps in cancer metastasis, which are the major cause of death in cancer patients. Tumor-associated macrophages (TAMs) and interstitial flow (IF) are two important biochemical and biomechanical cues in tumor microenvironment, play essential roles in tumor progression. However, their combined effects on tumor cell migration and invasion as well as molecular mechanism remains largely unknown. In this work, we developed a microfluidic-based 3D breast cancer model by co-culturing tumor aggregates, macrophages, monocytes and endothelial cells within 3D extracellular matrix in the presence of IF to study tumor cell migration and invasion. On the established platform, we can precisely control the parameters related to tumor microenvironment and observe cellular responses and interactions in real-time. When co-culture of U937 with human umbilical vein endothelial cells (HUVECs) or MDA-MB-231 cells and tri-culture of U937 with HUVECs and MDA-MB-231 cells, we found that mesenchymal-like MDA-MB-231 aggregates activated the monocytes to TAM-like phenotype macrophages. MDA-MB-231 cells and IF simultaneously enhanced the macrophages activation by the stimulation of colony-stimulating factor 1 (CSF-1). The activated macrophages and IF further promoted vascular sprouting via vascular endothelial growth factor (VEGFα) signal and tumor cell invasion. This is the first attempt to study the interaction between macrophages and breast cancer cells under IF condition. Taken together, our results provide a new insight to reveal the important physiological and pathological processes of macrophages-tumor communication. Moreover, our established platform with a more mimetic 3D breast cancer model has the potential for drug screening with more accurate results.
2019, 30(5): 1043-1050
doi: 10.1016/j.cclet.2019.01.011
Abstract:
Breast cancer is one of the most common cancers in the world, survival rates of breast cancer are rising as screening and treatment improve. Many new technologies applied in the biomedical domain have been born for rapid diagnosis and treatment. In this work, visualization cell microarray chip with three dimensional (3D) embedded cell scaffold for cell diagnosis and treatment was designed. DNA segment, targeting on breast cancer cells SK-BR-3, were modified with camptothecin and used as model drug. Cell microarray chip system successfully control the diffusion of small molecules and locally introduced the compounds into cells. 3D embedded cell scaffold in the cell array chip afforded an environment with continuous medium supplementary and help controlling the diffusion of small molecules drugs. By cell microarray chip system, SK-BR-3 was targeted screening and killing in one step. Cell microarray chip system can achieve accurate, rapid diagnosis and target treatment of breast cancer cells SK-BR-3 and have a potential to develop to be an effective and accurate drug screen method for evaluating the drug effect of the booming chemicals.
Breast cancer is one of the most common cancers in the world, survival rates of breast cancer are rising as screening and treatment improve. Many new technologies applied in the biomedical domain have been born for rapid diagnosis and treatment. In this work, visualization cell microarray chip with three dimensional (3D) embedded cell scaffold for cell diagnosis and treatment was designed. DNA segment, targeting on breast cancer cells SK-BR-3, were modified with camptothecin and used as model drug. Cell microarray chip system successfully control the diffusion of small molecules and locally introduced the compounds into cells. 3D embedded cell scaffold in the cell array chip afforded an environment with continuous medium supplementary and help controlling the diffusion of small molecules drugs. By cell microarray chip system, SK-BR-3 was targeted screening and killing in one step. Cell microarray chip system can achieve accurate, rapid diagnosis and target treatment of breast cancer cells SK-BR-3 and have a potential to develop to be an effective and accurate drug screen method for evaluating the drug effect of the booming chemicals.
2019, 30(5): 1051-1054
doi: 10.1016/j.cclet.2019.01.014
Abstract:
Heteroatom doped carbon dots (CDs) with distinct merits are of great attractions in various fields such as solar cells, catalysis, trace element detection and photothermal therapy. In this work, we successfully synthesized blue-fluorescence and photostability manganese-doped carbon dots (Mn-CDs) with a quantum yield up to 7.5%, which was prepared by a facile one-step hydrothermal method with sodium citrate and manganese chloride. The Mn-CDs is the high mono-dispersity, uniform spherical nanoparticles. The Mn element plays a critical role in achieving a high quantum yield in synthesis of carbon dots, which was confirmed by the structure analysis using XPS and FTIR. Spectroscopic investigations proved that the decent PLQY and luminescence properties of Mn-CDs are due to the heteroatom doped, oxidized carbon-based surface passivation. In addition, the Mn-CDs are demonstrated as promising fluorescent sensors for iron ions with a linear range of 0-500 μmol/L and a detection limit of 2.1 nmol/L (turn-off), indicating their great potential as a fluorescent probe for chemical sensing.
Heteroatom doped carbon dots (CDs) with distinct merits are of great attractions in various fields such as solar cells, catalysis, trace element detection and photothermal therapy. In this work, we successfully synthesized blue-fluorescence and photostability manganese-doped carbon dots (Mn-CDs) with a quantum yield up to 7.5%, which was prepared by a facile one-step hydrothermal method with sodium citrate and manganese chloride. The Mn-CDs is the high mono-dispersity, uniform spherical nanoparticles. The Mn element plays a critical role in achieving a high quantum yield in synthesis of carbon dots, which was confirmed by the structure analysis using XPS and FTIR. Spectroscopic investigations proved that the decent PLQY and luminescence properties of Mn-CDs are due to the heteroatom doped, oxidized carbon-based surface passivation. In addition, the Mn-CDs are demonstrated as promising fluorescent sensors for iron ions with a linear range of 0-500 μmol/L and a detection limit of 2.1 nmol/L (turn-off), indicating their great potential as a fluorescent probe for chemical sensing.
2019, 30(5): 1093-1096
doi: 10.1016/j.cclet.2018.11.008
Abstract:
The activity and stability of Cu nanostructures strongly depend on their sizes, morphology and structures. Here we report the preparation of two-dimensional (2D) Cu@Cu-BTC core-shell nanosheets (NSs). The thickness of the Cu NSs could be tuned to sub-10 nm through a mild etching process, in which the Cu-BTC in situ grow along with the oxidation on the surface of the Cu NSs. This unique strategy can also be extended to synthesize one-dimensional (1D) Cu@Cu-BTC nanowires (NWs). Furthermore, the obtained Cu@Cu-BTC NSs could be applied as an effective material to the memory device with the write-onceread-many times (WORM) behavior and the high ION/IOFF ratio (>2.7×103).
The activity and stability of Cu nanostructures strongly depend on their sizes, morphology and structures. Here we report the preparation of two-dimensional (2D) Cu@Cu-BTC core-shell nanosheets (NSs). The thickness of the Cu NSs could be tuned to sub-10 nm through a mild etching process, in which the Cu-BTC in situ grow along with the oxidation on the surface of the Cu NSs. This unique strategy can also be extended to synthesize one-dimensional (1D) Cu@Cu-BTC nanowires (NWs). Furthermore, the obtained Cu@Cu-BTC NSs could be applied as an effective material to the memory device with the write-onceread-many times (WORM) behavior and the high ION/IOFF ratio (>2.7×103).
2019, 30(5): 1097-1099
doi: 10.1016/j.cclet.2019.01.030
Abstract:
This contribution reports the immobilization of polyoxometalate (POM) into poly(4-vinyl pyridine) (P4VP) brushes and the controlled reduction of silver ions, in-situ generating metal nanoparticles in the brushes. P4VP brushes were straightforwardly created by UV-assisted photopolymerization of 4-vinyl pyridine (4VP) on silicon or glass substrates. Phosphotungstic acid (H3PW12O40), one of the most widely used Keggin-type POM was anchored onto these pyridine moieties through electrostatic interaction, leading to the P4VP/POM hybrid brushes. The immobilized POM was further reduced to heteropolyblue, which could be used to generate silver nanoparticles in a controlled fashion. AFM, UV-vis and IR characterization indicate that P4VP brushes not only provide an efficient platform in the controlled preparation of Ag nanoparticles, but also efficiently disperse and stabilize POM, thus preventing the aggregation of the generated Ag nanoparticles.
This contribution reports the immobilization of polyoxometalate (POM) into poly(4-vinyl pyridine) (P4VP) brushes and the controlled reduction of silver ions, in-situ generating metal nanoparticles in the brushes. P4VP brushes were straightforwardly created by UV-assisted photopolymerization of 4-vinyl pyridine (4VP) on silicon or glass substrates. Phosphotungstic acid (H3PW12O40), one of the most widely used Keggin-type POM was anchored onto these pyridine moieties through electrostatic interaction, leading to the P4VP/POM hybrid brushes. The immobilized POM was further reduced to heteropolyblue, which could be used to generate silver nanoparticles in a controlled fashion. AFM, UV-vis and IR characterization indicate that P4VP brushes not only provide an efficient platform in the controlled preparation of Ag nanoparticles, but also efficiently disperse and stabilize POM, thus preventing the aggregation of the generated Ag nanoparticles.
2019, 30(5): 1100-1104
doi: 10.1016/j.cclet.2018.11.027
Abstract:
In this study, a simple and efficient way is demonstrated to create strong interfacial interaction between graphene oxide (GO) filler and poly(vinyl alcohol) (PVA) matrix through metal ion coordination. The coordination bonding provides efficient load transfer during the tensile process, and enhances the mechanical properties of the nanocomposites significantly. After being coordinated with Cu(Ⅱ) ions, GO/ PVA composites show much higher Young's moduli and yield stresses than pure PVA and noncoordinated GO/PVA. UV-vis and FTIR spectra are performed to confirm the successful coordination between GO and PVA. Ethylene diamine tetraacetic acid disodium salt (EDTA-2Na) is used to confirm the important role of coordination in enhancing the composites. This research provides a new approach to manufacture polymer-matrix nanocomposites with significantly improved mechanical performances.
In this study, a simple and efficient way is demonstrated to create strong interfacial interaction between graphene oxide (GO) filler and poly(vinyl alcohol) (PVA) matrix through metal ion coordination. The coordination bonding provides efficient load transfer during the tensile process, and enhances the mechanical properties of the nanocomposites significantly. After being coordinated with Cu(Ⅱ) ions, GO/ PVA composites show much higher Young's moduli and yield stresses than pure PVA and noncoordinated GO/PVA. UV-vis and FTIR spectra are performed to confirm the successful coordination between GO and PVA. Ethylene diamine tetraacetic acid disodium salt (EDTA-2Na) is used to confirm the important role of coordination in enhancing the composites. This research provides a new approach to manufacture polymer-matrix nanocomposites with significantly improved mechanical performances.
2019, 30(5): 1105-1110
doi: 10.1016/j.cclet.2018.12.024
Abstract:
Recently, because of excellent electrical conductivities and many active sites, transition metal sulfides have been utilized as efficient electrodes for supercapacitors. Herein, we synthesize hierarchical MoS2/Ni3S2 structures grown on nickel foam by a facile one-pot hydrothermal process. The as-fabricated asymmetric hybrid capacitor based on hierarchical MoS2/Ni3S2 electrode exhibit a specific capacitance of ~1.033 C/cm2 at 1 mA/cm2. Furthermore, the hybrid capacitor unveils an energy density of 35.93 mWh/cm3 at a power density of 1064.76mW/cm3. The observed results clearly revealed that the synthesizedMoS2/Ni3S2 structure might be used as potential electrode material for future energy storage devices.
Recently, because of excellent electrical conductivities and many active sites, transition metal sulfides have been utilized as efficient electrodes for supercapacitors. Herein, we synthesize hierarchical MoS2/Ni3S2 structures grown on nickel foam by a facile one-pot hydrothermal process. The as-fabricated asymmetric hybrid capacitor based on hierarchical MoS2/Ni3S2 electrode exhibit a specific capacitance of ~1.033 C/cm2 at 1 mA/cm2. Furthermore, the hybrid capacitor unveils an energy density of 35.93 mWh/cm3 at a power density of 1064.76mW/cm3. The observed results clearly revealed that the synthesizedMoS2/Ni3S2 structure might be used as potential electrode material for future energy storage devices.
2019, 30(5): 1111-1114
doi: 10.1016/j.cclet.2018.12.026
Abstract:
Ceramic and polytetrafluoroethylene composites as dielectric materials have a low dielectric loss at high frequency and play an important role in the modern communication field. However, room temperature phase transformation of PTFE resins, which is accompanied by a large volume change (> 400 ppm/℃), seriously affects the dimensional stability and performance stability of materials. The LD125 modified glass fiber (GF) was introduced to the CaO-Li2O-Sm2O3-TiO2 (CLST)/PTFE composite, to reduce the thermal expansion coefficient (CTE) of the composites. The tri-phase composites (CLST/PTFE/GF) show the low dielectric loss and excellent machine-ability. The effect of GF content on the dielectric properties and CTE was also investigated. The CLST/PTFE filled with 5% GF exhibits the best overall performance, which is a promising microwave dielectric material for microwave communication.
Ceramic and polytetrafluoroethylene composites as dielectric materials have a low dielectric loss at high frequency and play an important role in the modern communication field. However, room temperature phase transformation of PTFE resins, which is accompanied by a large volume change (> 400 ppm/℃), seriously affects the dimensional stability and performance stability of materials. The LD125 modified glass fiber (GF) was introduced to the CaO-Li2O-Sm2O3-TiO2 (CLST)/PTFE composite, to reduce the thermal expansion coefficient (CTE) of the composites. The tri-phase composites (CLST/PTFE/GF) show the low dielectric loss and excellent machine-ability. The effect of GF content on the dielectric properties and CTE was also investigated. The CLST/PTFE filled with 5% GF exhibits the best overall performance, which is a promising microwave dielectric material for microwave communication.
2019, 30(5): 1115-1120
doi: 10.1016/j.cclet.2019.01.004
Abstract:
Ternary nanocomposites of CuxZnySnzS(x+y+z) are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability. Recently, this nanocomposite used as anode material for Li-ion battery has been reported, but there is limited research on its application in supercapacitors which is considered a complementary energy storage device to battery. In this work, flower-like Cu5Sn2S7/ZnS and pristine Cu5Sn2S7 nanocomposite were prepared via a facile hydrothermal method. The electrochemical tests showed that the Cu5Sn2S7/ZnS nanocomposite exhibited better performance than pristine Cu5Zn2S7, suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu5Sn2S7, with the good capacitance of 200 F/g at the current density of 1 A/g. Furthermore 170 F/g was obtained at the large current density of 10 A/g. Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.
Ternary nanocomposites of CuxZnySnzS(x+y+z) are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability. Recently, this nanocomposite used as anode material for Li-ion battery has been reported, but there is limited research on its application in supercapacitors which is considered a complementary energy storage device to battery. In this work, flower-like Cu5Sn2S7/ZnS and pristine Cu5Sn2S7 nanocomposite were prepared via a facile hydrothermal method. The electrochemical tests showed that the Cu5Sn2S7/ZnS nanocomposite exhibited better performance than pristine Cu5Zn2S7, suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu5Sn2S7, with the good capacitance of 200 F/g at the current density of 1 A/g. Furthermore 170 F/g was obtained at the large current density of 10 A/g. Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.
2019, 30(5): 1121-1125
doi: 10.1016/j.cclet.2019.01.009
Abstract:
Graphene surface modification by heteroatom incorporation is an attractive strategy to construct flexible electrochemical capacitors. Herein, the steam-assistant heteroatoms of sulfur and phosphorus dualdoped graphene film (s-SPG) is fabricated via an ice-template and thermal-activation approach and they demonstrate an excellent pseudocapacitive behavior in flexible electrochemical capacitors. As probed by various microscopic and spectroscopic analysis, well-maintained porosity structure is formed during the freeze-drying and steam-activation treatment; the increased surface roughness is ascribed to heteroatoms doping by the formation of S- and P-containing functional groups as electrochemical active sites. A flexible device integrated by porous s-SPG film shows high pseudocapacitive behavior with high specific capacitance (169 F/g), rate capability (91.7%) and cyclic stability (92.5%). Even at the bend angle of 120°, no obvious change of specific capacitance is found indicating a good flexibility of s-SPG devices; the current study shows that s-SPG is a very promising electrode to realize the practical applications of all solid flexible supercapacitors.
Graphene surface modification by heteroatom incorporation is an attractive strategy to construct flexible electrochemical capacitors. Herein, the steam-assistant heteroatoms of sulfur and phosphorus dualdoped graphene film (s-SPG) is fabricated via an ice-template and thermal-activation approach and they demonstrate an excellent pseudocapacitive behavior in flexible electrochemical capacitors. As probed by various microscopic and spectroscopic analysis, well-maintained porosity structure is formed during the freeze-drying and steam-activation treatment; the increased surface roughness is ascribed to heteroatoms doping by the formation of S- and P-containing functional groups as electrochemical active sites. A flexible device integrated by porous s-SPG film shows high pseudocapacitive behavior with high specific capacitance (169 F/g), rate capability (91.7%) and cyclic stability (92.5%). Even at the bend angle of 120°, no obvious change of specific capacitance is found indicating a good flexibility of s-SPG devices; the current study shows that s-SPG is a very promising electrode to realize the practical applications of all solid flexible supercapacitors.
2019, 30(5): 1126-1128
doi: 10.1016/j.cclet.2019.02.034
Abstract:
In this study, a fingerprint analysis method along with the EEM fluorescence spectra was used to characterize the SAPs released by Scenedesmus sp. LX1 during the growth process. Resin fractionation was used firstly to divide the SAPs into six resin fractions, and then size exclusion chromatography (SEC) was performed to separate each resin fraction into several subfractions with different molecular weights (MW). The fingerprint graph integrated the information revealed by resin fractionation as well as that by SEC, showing that main components of SAPs changed from the hydrophilic subfractions with MW of 102-103 Da to the hydrophobic subfractions with MW of 103-104 Da. Comparing these results with the EEM fluorescence spectra of different resin fractions, the change of the main matters within SAPs could be inferred.
In this study, a fingerprint analysis method along with the EEM fluorescence spectra was used to characterize the SAPs released by Scenedesmus sp. LX1 during the growth process. Resin fractionation was used firstly to divide the SAPs into six resin fractions, and then size exclusion chromatography (SEC) was performed to separate each resin fraction into several subfractions with different molecular weights (MW). The fingerprint graph integrated the information revealed by resin fractionation as well as that by SEC, showing that main components of SAPs changed from the hydrophilic subfractions with MW of 102-103 Da to the hydrophobic subfractions with MW of 103-104 Da. Comparing these results with the EEM fluorescence spectra of different resin fractions, the change of the main matters within SAPs could be inferred.
2019, 30(5): 1129-1132
doi: 10.1016/j.cclet.2019.01.025
Abstract:
In this study, batch experiments were conducted to investigate the performance of microscale Fe/Cu bimetallic particles-air-persulfate system (mFe/Cu-air-PS) for p-nitrophenol (PNP) treatment in aqueous solution. First, the optimal operating parameters (i. e., aeration rate of 1.0 L/min, theoretical Cu mass loading (TMLCu) of 0.110 g Cu/g Fe, mFe/Cu dosage of 15 g/L, PS total dosage of 15 mmol/L, feeding times of PS of 5, initial pH 5.4) were obtained successively by single-factor experiments. Under the optimal conditions, high COD and TOC removal efficiencies (71.0%, 65.8%) were obtained after 60 min treatment. Afterword, compared with control experiments (i. e., mFe/Cu, air, PS, mFe/Cu-air, mFe/Cu-PS, air-PS and mFe-air-PS), mFe/Cu-air-PS system exerted superior performance for pollutants removal due to the synergistic effect between mFe/Cu, air and PS. In addition, the results of control experiments and radical quenching experiments indicate this reinforcement by feeding of PS was greater than by aeration in mFe/ Cu-air-PS system. Furthermore, the degradation intermediates of PNP in mFe/Cu-air-PS process were identified and measured by HPLC. Based on the detected intermediates, the degradation pathways of PNP were proposed comprehensively, which revealed that toxic and refractory PNP in aqueous solution could be decomposed effectively and transformed into lower toxicity intermediates. As a result, mFe/Cu-air-PS system with the performance of oxidation combined reduction can be also a potential technology for the treatment of toxic and refractory PNP contained wastewater.
In this study, batch experiments were conducted to investigate the performance of microscale Fe/Cu bimetallic particles-air-persulfate system (mFe/Cu-air-PS) for p-nitrophenol (PNP) treatment in aqueous solution. First, the optimal operating parameters (i. e., aeration rate of 1.0 L/min, theoretical Cu mass loading (TMLCu) of 0.110 g Cu/g Fe, mFe/Cu dosage of 15 g/L, PS total dosage of 15 mmol/L, feeding times of PS of 5, initial pH 5.4) were obtained successively by single-factor experiments. Under the optimal conditions, high COD and TOC removal efficiencies (71.0%, 65.8%) were obtained after 60 min treatment. Afterword, compared with control experiments (i. e., mFe/Cu, air, PS, mFe/Cu-air, mFe/Cu-PS, air-PS and mFe-air-PS), mFe/Cu-air-PS system exerted superior performance for pollutants removal due to the synergistic effect between mFe/Cu, air and PS. In addition, the results of control experiments and radical quenching experiments indicate this reinforcement by feeding of PS was greater than by aeration in mFe/ Cu-air-PS system. Furthermore, the degradation intermediates of PNP in mFe/Cu-air-PS process were identified and measured by HPLC. Based on the detected intermediates, the degradation pathways of PNP were proposed comprehensively, which revealed that toxic and refractory PNP in aqueous solution could be decomposed effectively and transformed into lower toxicity intermediates. As a result, mFe/Cu-air-PS system with the performance of oxidation combined reduction can be also a potential technology for the treatment of toxic and refractory PNP contained wastewater.
