Fabrication, Characterization And Applications Of A Single-walled Carbon Nanotube Electrode

This thesis investigated the fabrication and characterization of singled-walled carbon nanotube modified electrode (SCNT/GC) electrode. Extensive studies were made on the applications of the electrodes to immobilization and direct electrochemistry of heme-contained protein (Cyto c) on the surface of SCNT. The method presented here can be easily extended to immobilize and obtain the direct electrochemistry of other redox enzymes or proteins. The electrochemical biosensor based on immobilization of oxidase (glucose oxidase, GOx) on SCNT was fabrication and its performances were also characterized. The main results of this research were expressed as follows:1. A single-walled carbon nanotube modified electrode (SCNT/GC) was fabricated and characterized by techniques of scan electron microscopy (SEM), Raman spectrum, FT-IR spectroscopy and Electrochemical impedance spectroscopy (EIS). The results showed that the electrochemical reaction resistance of SCNT/GC electrode was much lower than that of bare GC electrode (in the systen of 5 mmol/L Fe(CN)₆^3-/4- + 0.1 mol/L KCl), indicating that the rate of the electrochemical reaction of Fe(CN)₆^3-/4- was rapid at SCNT in comparison with that at bare GC electrode.2. Cytochrome c (Cyto c) was immobilized on the surface of the single-wall carbon nanotube (SCNT) by the method of adsorption. Infrared spectroscopy indicated that Cyto c remained in its original structure and did not undergo structural change after its immobilization on the SCNT. The direct electrochemistry of Cyto c, which was adsorbed on the surface of the SCNT, was studied by cyclic voltammetry. The voltammetric results from demonstrated that the SCNT had promotional effects on the direct electron transfer of Cyto c and also indicated that the immobilized Cyto c retained its bioelectrocatalytic activity to the reduction of H₂O₂. This modified electrode might be used in development of new biosensors and the biofuel cells.