Characterization And Analysis Application Research Of High Temperature Oxidation Treatment Carbon Fiber Electrode

As a common microelectrode,carbon fiber electrode(CFE)is not only have many excellent characteristics of microelectrode,such as low IR,fast mass transfer rate,small time constant and high current density,but also have unique properties of carbon electrode,for example,chemical inertness,high stability and wide potential window.Therefore,CFE is widely used in the fields of electrode reactions kinetics,single molecule detection,single nanoparticle detection,single cell detection,electrochemical biosensor,and in vivo real-time monitoring.But the surface inertia of the electrode affect its application to some extent.Therefore,it is of great significance to study the functional method of CFE,develop a new modified CFE and study its application.In this paper,a new method for modification of CFE was developed,and the treated CFEs were characterized and applied.This thesis mainly includes the following three chapters:The first chapter is the review part.In this part,we briefly introduces the concept and advantages of the microelectrode,mainly introduces the characterization of the microelectrode,the preparation and application of CFE,and focuses on the functional methods of CFE.Finally,the research background and significance of this thesis are described.In chapter 2,the heat-treated carbon fiber electrode was characterized and applied.In this work,a new modified carbon fiber electrode was prepared by means of high-temperature oxidation method.The surface structure and electrochemical properties of the modified CFEs were analyzed and characterized,and uric acid was taken as a model to study the analytical application of the heat-treated CFE.The results showed that the surface roughness of the treated carbon fiber electrode increased,the surface area and the electrode activity increased.The pore structure increased the exposed amino group,the positive charge and hydrophilicity of the electrode surface increased.Due to the above characteristics,heat-treated CFE had a good catalytic effect on negatively charged electroactive small molecule,such as potassium ferricyanide and uric acid.The steady-state current in uric acid solution with different concentrations was linear with its concentration.This method of making modified electrode didn't need to assemble other active substances.It was simple,convenient and low cost.In chapter 3,the CFE treated by high-temperature oxidation is further characterized by electrochemiluminescence(ECL)and its analytical applicaton is investigated.The ECL intensity of luminol obtained at heat-treated CFE were improved obviously.Based on the results in first work,we speculated that the inner of the holes was the fresh carbon surface.The surface of heat-treated CFE and the hole wall was hydrophobic.The electrooxidization of luminol took place at the fresh carbon surface whice had electro-catalytic activity.However,the subsequent chemiluminescent reaction occurred near the hole wall,which was hydrophobic and in favor of the luminol chemiluminescent reaction.So,the ECL quantum yield was enhanced.In addition,hydrogen peroxide was taken as a model to investigate the analytical application of the heat-treated CFE.