Research On Construction And Biosensing Performance Of Porous Gold Based Triphase Interfacial Enzyme Electrode

Electrochemical biosensors play an irreplaceable role in the medical and environmental fields.The electrochemical biosensor based on oxidase is one of the most widely used devices.In the presence of oxygen,the target analytes are catalyzed and oxidized by a specific oxidase to generate hydrogen peroxide in the same proportion as the substrate.By detecting the production of hydrogen peroxide,the concentration of the target analytes can be indirectly determined.However,when the traditional solid-liquid diphase biosensor detects the target analytes,the supply of oxygen is completely dependent on the liquid phase.Due to the low oxygen content and slow transmission rate in the liquid phase,the oxygen content at the reaction interface is insufficient and the oxygen content fluctuates severely,which greatly limits the linear range and accuracy of sensor detection.The construction of the superhydrophobic solid-liquid-gas triphase interface makes the oxygen supply in the reaction change from the liquid phase to the gas phase,which provides a new idea for solving the above problems.Therefore,the development of a triphase interface electrochemical biosensor is of great significance to the development of high-efficiency electrochemical biosensing technology.The microstructure of the material surface plays a vital role in the construction of the superhydrophobic triphase interface,and the exploration of the microstructure has become a hot spot in today’s research.In this thesis,based on the bubble template electrochemical deposition method,the porous gold nanostructure is deposited on the surface of the metal electrode,and the superhydrophobic solid-liquid-gas triphase interface is constructed through the superhydrophobic treatment.And studied its enzyme kinetics and its application in electrochemical enzyme biosensing.The main research contents of this paper are as follows:1.Prepared porous gold substrate based triphase enzyme electrode and explored its biosensing performance:By changing the electrodeposition time,a series of honeycomb porous gold substrate with different thicknesses were obtained.Based on the porous Au substate,we constructed solid-liquid-gas triphase interface enzyme electrode,and explored the influence of interface microenvironment on the kinetics of enzyme catalytic reactions.Taking glucose as a model analyte,the biosensing performance of triphase enzyme electode was studied.2.Explored the effects of different interfacial microenvironments on the performance of enzymatic reaction and enzyme electrode.On the basis of porous Au deposited on flat Au substrate,titanium mesh,and porous Au deposited on titanium mesh,we construct triphase enzyme electrode with nano,micro,and micro/nano-composite structure interface microenvironment.Evaluated the performance of triphase enzyme electrodes with different interfacial microstructures from the perspective of enzyme kinetics and electrochemical performance,and found that the enzyme electrode with micro/nano-composite interfacial structure had the best biosensing performance.