| In recent years,enzyme-based biosensors have been relatively mature in the field of biosensing.However,there are still some defects.For example,the thermal stability,anti-interference,and acid and alkali resistance of the catalytic performance of the enzyme biosensors all need to be improved,and the preparation method of the enzyme-based electrode is relatively complicated,resulting in a relatively high cost.After the immobilization of the enzyme molecules on the carrier,efficient direct electron transfer between the solid enzyme carrier and the oxidoreductase active center is difficult to achieve.According to literature reports,aromatic heterocyclic rings and large conjugated ?-bonded aromatic compounds are conducive to efficient direct electron transfer.Porous three-dimensional materials not only have good conductivity but also maintain the active configuration in protein molecules.Due to the complexity of heterogeneous catalytic kinetics,few literatures reported the mechanism of heterogeneous catalytic kinetics and did not determine the rate-determining step of the entire catalytic cycle.In view of the above problems,several aromatic heterocyclic rings and large conjugated ?-bonded aromatic compounds were selected as the immobilized enzyme carrier,and the immobilized enzyme electrode was prepared by chemical coupling.The effect of enzyme-carrier interactions on the chemical properties of the enzyme was investigated by spectroscopic methods.Electrochemical methods were used to study the direct electrochemistry of the immobilized electrode and the catalytic properties of the relevant substrates.The immobilized enzyme was evaluated as an enzyme-based electrophoresis.The performance of a chemical sensor determines the key steps in the catalytic performance of an enzyme-based electrode by analyzing the kinetics of an enzyme-catalyzed reaction.1 The laccase immobilized chitosan-multiwall carbon nanoparticle was studied under the condition that the amount of substrate and electron mediator retained in the modified layer of the anaerobic nanocomposite were respectively negligible relative to the total amount of these substances in the bulk.Heterogeneous Catalytic Kinetics of Oxygen Reduction in Tube Composite Modified Glassy Carbon Electrode.The test results show that under the premise that the retention of the medium and the substrate in the matrix can be neglected,the rate constant of each step in the catalytic cycle is normalized to the same unit and compared,and the diffusion of the electron mediator is obtained as The speed of the entire catalytic cycle.2 Magnetic nanocomposites with Fe3O4 as the core and carboxymethylated chitosan as the shell were used to immobilize the electron mediator and myoglobin by chemical coupling to prepare a biocathode based on Mb.Methods Detect direct electron transfer and catalyze the reduction of H2O2.The analysis of the results showed that adjacent complexes between the heteroatoms in the polymer and the cofactors in the electron mediator/enzyme redox site will have a great influence on the spectral and electrochemical properties of the protein.These interactions change the pathway and catalytic mechanism of electron transfer3 A novel immobilized myoglobin-based electrode was prepared by coupling 4-mercaptobenzoic acid and 4-mercaptobenzoic acid functionalized nano-sized gold particles with multi-walled carbon nanotubes as the immobilized enzyme carrier,and the effective electron transfer of the immobilized enzyme electrode was studied.Catalytic hydrogen peroxide reduction properties.The experimental results show that the catalytic activity and the H2O2 concentration of the two immobilized electrodes in the H2O2 concentration range from 1.506 to 3.237 ?mol/L.The linear relationship between the catalytic current and the H2O2 concentration is good.The detection limits of H2O2 can reach 0.268 ?mol/L and 0.302 ?mol/L,respectively.L.The Michaelis constants of H2O2 are 16.12 ?/L and 23.81 ?mol/L,respectively. |
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