Salt severely restricts cotton(Gossypium hirsutum) growth and production.The present study was undertaken to study the effect of salt-induced hydrogen peroxide(H_2O_2) on antioxidant enzymes in cotton.Na Cl treatment ...Salt severely restricts cotton(Gossypium hirsutum) growth and production.The present study was undertaken to study the effect of salt-induced hydrogen peroxide(H_2O_2) on antioxidant enzymes in cotton.Na Cl treatment or exogenous H_2O_2 was used to investigate the relationship between H_2O_2 content and levels of antioxidant enzymes including superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POD),and catalase(CAT),as well as the transcriptional levels of corresponding genes.H_2O_2 content increased within 24 h following 200 mmol L^(–1)Na Cl treatment.Both Na Cl-induced and exogenous H_2O_2 increased the activity of antioxidant enzymes including APX and SOD and upregulated the transcriptional levels of Ghc APX1,Gh Fe SOD,and Ghchl CSD.These increased activities and upregulated transcriptional levels were inhibited when the salt-induced H_2O_2 was scavenged by NAC.These results indicate that salt-induced H_2O_2 as a second signaling messenger modulates APX and SOD activities by regulating the transcription levels of corresponding genes,alleviating oxidative stress,and increasing salt tolerance in cotton.展开更多
In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-P...In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [Ci2mim]Br-PPy (Ci2~PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, Ci2?PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained Ci2~PPy^Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel Ci2-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared Ci2-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.展开更多
In this study, Mn(Ⅱ) as a mimetic enzyme of horseradish peroxidase (HRP) was applied to the determination of hydrogen peroxide (H2O2). The method introduced in this paper is based on Mn(Ⅱ)’s catalytic effect on t...In this study, Mn(Ⅱ) as a mimetic enzyme of horseradish peroxidase (HRP) was applied to the determination of hydrogen peroxide (H2O2). The method introduced in this paper is based on Mn(Ⅱ)’s catalytic effect on the oxidation of 4-aminoantipyrine(4-AAP) with modified Trinder’s reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3, 5-dimethoxyaniline(DAOS) by H2O2. By coupling this mimetic catalytic reaction with the catalytic reaction of glucose oxidase (GOD), glucose can be detected. Under optimum conditions, the calibration graphs for the determination of H2O2 and glucose are in the range of 1.0×10-3?1.0×10-1 mol/L and 1.0×10-3?14×10-3 mol/L respectively. The detection limit is 5.9×10-4 mol/L for H2O2 and is 9.2×10-4 mol/L for glucose. The feasibility of Mn ( II ) as a HRP mimetic enzyme in practical clinical analysis has been proven in the determination of glucose in human serum. So far, Mn ( II ) is the simplest and the most inexpensive mimetic enzyme.展开更多
The characteristic of Myoglobin as mimetic enzyme was studied and applied in the determination of HeO2 with o-phenylenediamine as substrate. The absorbanee obtained at 40 ℃ was found to be proportional to the concent...The characteristic of Myoglobin as mimetic enzyme was studied and applied in the determination of HeO2 with o-phenylenediamine as substrate. The absorbanee obtained at 40 ℃ was found to be proportional to the concentration of H2O2 in the range of 2.0×10^-5- 2.0×10^-7 mol/L, with a correlation coefficient of 0.999 1. The proposed meth od is simple and highly sensitive to a detection limit of 2.7 × 10^-8 mol/L. The relative standard deviations were within 5% for the determination of different concentrations of H2O2. Satisfied results were obtained in the determination of H2O2 in rainwater by this method, and the recoveries were at the range of 97.2%-105.4%.展开更多
Salvianolic acid B(Sal B) is an active component of traditional Chinese medicine Salvia miltiorrhiza and is used to treat vascular diseases. To better understand its mechanism, the antioxidant capacities of Sal B was ...Salvianolic acid B(Sal B) is an active component of traditional Chinese medicine Salvia miltiorrhiza and is used to treat vascular diseases. To better understand its mechanism, the antioxidant capacities of Sal B was evaluated with human endothelial cells under oxidative stress. Human endothelial cells were pretreated with Sal B for 12 h followed by hydrogen peroxide for another 12 h. Production of reactive oxygen species (ROS), activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and concentration of glu-tathione were measured. Protective effect of Sal B on the endothelial cells from hydrogen peroxide-induced damage was observed, and ROS production in the cells was found significantly inhibited. Sal B remarkably enhanced the activities of antioxidant enzymes SOD, CAT and GPX. Furthermore, Sal B up-regulated the intracellular glu-tathione concentration. The results indicate that Sal B protected endothelial cells from oxidative stress by improving the redox status of the cells through enhancing the antioxidant enzyme activities and increasing the reductive glu-tathione concentration after the oxidative challenge.展开更多
This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst.The effecting factors during degradation and the degrading mechan...This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst.The effecting factors during degradation and the degrading mechanism were studied.Also,the location of the enzyme in the cell,which could catalyze the degradation of 4-aminophenol,was analyzed.The results showed that to degrade 50 mL of 4-aminophenol whose concentration was 500 mg/L,the optimal conditions were:volume of H_(2)O_(2)=3 mL,temperature=40-60°C and pH=9-10.In the degra-dation process,4-aminophenol was first converted to benzo-quinone and NH3,then organic acids including maleic acid,fumaleic acid,and oxalic acid were formed,and then finally CO_(2) and H2O were generated as final products.The enzyme that could catalyze the degradation of 4-aminophenol was mainly extracellular enzyme.展开更多
A cubic Prussian blue （PB） with the hollow interior was successfully synthesized by direct dissociation followed by a controlled self-etching process. The etching process also made hollow Prussian blue （HPB） a por...A cubic Prussian blue （PB） with the hollow interior was successfully synthesized by direct dissociation followed by a controlled self-etching process. The etching process also made hollow Prussian blue （HPB） a porous structure. SEM, TEM and XRD were employed to confirm the structure and morphology of the prepared materials. Then HPB and chitosan （CS） were deposited on a glassy carbon electrode （GCE）, used to determine H202. The amperometric performance of HPB/CS/GCE was investigated. It was found that the special structure of HPB exhibits enhanced performance in the H202 sensing.展开更多
Hydrogen peroxide(H_(2)O_(2))is a very simple bioactive small molecule.In living organisms,H_(2)O_(2)plays an important role in intracellular signaling.It is involved in many physiological processes including cellular...Hydrogen peroxide(H_(2)O_(2))is a very simple bioactive small molecule.In living organisms,H_(2)O_(2)plays an important role in intracellular signaling.It is involved in many physiological processes including cellular physiology,intracellular signaling,oxidative damage and disease progression.The tumor microenvironment enriched with H_(2)O_(2).Several electrochemical sensors have been developed and some have been put on the market.Such electrochemical sensors provide efficient,cost-effective,rapid and highly selective method of H_(2)O_(2)detection.So far,much progress has been made in the designing of materials and construction of H_(2)O_(2)sensors.This review describes the advances in the application of H_(2)O_(2)electrochemical sensors in cell detection.Enzyme-based sensors have been applied in diverse applications.In addition,recent advancements in nanotechnology have improved the development of nanozymes-based sensors.The application of noble metals,metal oxides,polymers,carbon materials and other two-dimensional materials in the design of H_(2)O_(2)sensors are discussed in detail.Moreover,the bio-stimulant types of H_(2)O_(2)sensor are summarized.Finally,the challenges and future perspectives in the application of H_(2)O_(2)electrochemical sensors in biological detection are discussed.展开更多
基金financially supported by the Joint Funds of the National Natural Science Foundation of China and Xinjiang Province (No.U1303282)
文摘Salt severely restricts cotton(Gossypium hirsutum) growth and production.The present study was undertaken to study the effect of salt-induced hydrogen peroxide(H_2O_2) on antioxidant enzymes in cotton.Na Cl treatment or exogenous H_2O_2 was used to investigate the relationship between H_2O_2 content and levels of antioxidant enzymes including superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POD),and catalase(CAT),as well as the transcriptional levels of corresponding genes.H_2O_2 content increased within 24 h following 200 mmol L^(–1)Na Cl treatment.Both Na Cl-induced and exogenous H_2O_2 increased the activity of antioxidant enzymes including APX and SOD and upregulated the transcriptional levels of Ghc APX1,Gh Fe SOD,and Ghchl CSD.These increased activities and upregulated transcriptional levels were inhibited when the salt-induced H_2O_2 was scavenged by NAC.These results indicate that salt-induced H_2O_2 as a second signaling messenger modulates APX and SOD activities by regulating the transcription levels of corresponding genes,alleviating oxidative stress,and increasing salt tolerance in cotton.
基金the National Natural Science Foundation of China(Project No.21476072)the Fundamental Research Funds for the Central Universities.
文摘In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [Ci2mim]Br-PPy (Ci2~PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, Ci2?PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained Ci2~PPy^Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel Ci2-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared Ci2-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.
文摘In this study, Mn(Ⅱ) as a mimetic enzyme of horseradish peroxidase (HRP) was applied to the determination of hydrogen peroxide (H2O2). The method introduced in this paper is based on Mn(Ⅱ)’s catalytic effect on the oxidation of 4-aminoantipyrine(4-AAP) with modified Trinder’s reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3, 5-dimethoxyaniline(DAOS) by H2O2. By coupling this mimetic catalytic reaction with the catalytic reaction of glucose oxidase (GOD), glucose can be detected. Under optimum conditions, the calibration graphs for the determination of H2O2 and glucose are in the range of 1.0×10-3?1.0×10-1 mol/L and 1.0×10-3?14×10-3 mol/L respectively. The detection limit is 5.9×10-4 mol/L for H2O2 and is 9.2×10-4 mol/L for glucose. The feasibility of Mn ( II ) as a HRP mimetic enzyme in practical clinical analysis has been proven in the determination of glucose in human serum. So far, Mn ( II ) is the simplest and the most inexpensive mimetic enzyme.
基金Supported by the National Natural Science Foun-dation of China (20275027) the Natural Science Foundation ofHubei Province (2004ABA182) .
文摘The characteristic of Myoglobin as mimetic enzyme was studied and applied in the determination of HeO2 with o-phenylenediamine as substrate. The absorbanee obtained at 40 ℃ was found to be proportional to the concentration of H2O2 in the range of 2.0×10^-5- 2.0×10^-7 mol/L, with a correlation coefficient of 0.999 1. The proposed meth od is simple and highly sensitive to a detection limit of 2.7 × 10^-8 mol/L. The relative standard deviations were within 5% for the determination of different concentrations of H2O2. Satisfied results were obtained in the determination of H2O2 in rainwater by this method, and the recoveries were at the range of 97.2%-105.4%.
基金Supported by National Natural Science Foundation of China (No30873400)Natural Science Foundation of Tianjin (No06YFJMC07300)
文摘Salvianolic acid B(Sal B) is an active component of traditional Chinese medicine Salvia miltiorrhiza and is used to treat vascular diseases. To better understand its mechanism, the antioxidant capacities of Sal B was evaluated with human endothelial cells under oxidative stress. Human endothelial cells were pretreated with Sal B for 12 h followed by hydrogen peroxide for another 12 h. Production of reactive oxygen species (ROS), activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and concentration of glu-tathione were measured. Protective effect of Sal B on the endothelial cells from hydrogen peroxide-induced damage was observed, and ROS production in the cells was found significantly inhibited. Sal B remarkably enhanced the activities of antioxidant enzymes SOD, CAT and GPX. Furthermore, Sal B up-regulated the intracellular glu-tathione concentration. The results indicate that Sal B protected endothelial cells from oxidative stress by improving the redox status of the cells through enhancing the antioxidant enzyme activities and increasing the reductive glu-tathione concentration after the oxidative challenge.
基金This study was supported by the Student Science and Technology Innovation Project of Hefei University of Technology.
文摘This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst.The effecting factors during degradation and the degrading mechanism were studied.Also,the location of the enzyme in the cell,which could catalyze the degradation of 4-aminophenol,was analyzed.The results showed that to degrade 50 mL of 4-aminophenol whose concentration was 500 mg/L,the optimal conditions were:volume of H_(2)O_(2)=3 mL,temperature=40-60°C and pH=9-10.In the degra-dation process,4-aminophenol was first converted to benzo-quinone and NH3,then organic acids including maleic acid,fumaleic acid,and oxalic acid were formed,and then finally CO_(2) and H2O were generated as final products.The enzyme that could catalyze the degradation of 4-aminophenol was mainly extracellular enzyme.
文摘A cubic Prussian blue （PB） with the hollow interior was successfully synthesized by direct dissociation followed by a controlled self-etching process. The etching process also made hollow Prussian blue （HPB） a porous structure. SEM, TEM and XRD were employed to confirm the structure and morphology of the prepared materials. Then HPB and chitosan （CS） were deposited on a glassy carbon electrode （GCE）, used to determine H202. The amperometric performance of HPB/CS/GCE was investigated. It was found that the special structure of HPB exhibits enhanced performance in the H202 sensing.
基金financially supported by the National Natural Science Fund(NSFC,Nos.U21A20417,31930067,31525009)the 1·3·5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(No.ZYGD18002)the support by the Fundamental Research Funds for the Central Universities
文摘Hydrogen peroxide(H_(2)O_(2))is a very simple bioactive small molecule.In living organisms,H_(2)O_(2)plays an important role in intracellular signaling.It is involved in many physiological processes including cellular physiology,intracellular signaling,oxidative damage and disease progression.The tumor microenvironment enriched with H_(2)O_(2).Several electrochemical sensors have been developed and some have been put on the market.Such electrochemical sensors provide efficient,cost-effective,rapid and highly selective method of H_(2)O_(2)detection.So far,much progress has been made in the designing of materials and construction of H_(2)O_(2)sensors.This review describes the advances in the application of H_(2)O_(2)electrochemical sensors in cell detection.Enzyme-based sensors have been applied in diverse applications.In addition,recent advancements in nanotechnology have improved the development of nanozymes-based sensors.The application of noble metals,metal oxides,polymers,carbon materials and other two-dimensional materials in the design of H_(2)O_(2)sensors are discussed in detail.Moreover,the bio-stimulant types of H_(2)O_(2)sensor are summarized.Finally,the challenges and future perspectives in the application of H_(2)O_(2)electrochemical sensors in biological detection are discussed.
