Studies On The New Carbon Materials Modified Electrodes In Electroanalytical Application

In this dissertation, efforts have been devoted to the fabrication and basic research in electroanalytical applications of novel carbon materials modified electrodes. The dissertation consists of two main parts: one is electroanalytical applications of carbon nanofibers paste modified electrode and the other is the electrochemical electrocatalytic oxidation of NADH with 1, 10-phenanthroline-5,6-dione functionalized ordered mesoporous carbon (PD/OMC) composite film modified electrode . The main works of the dissertation are as follows:1) Surface renewable carbon nanofibers paste electrodes (CNFPE) were fabricated by mechanical mixing carbon nanofibers (CNF) with mineral oil. The electrochemical behavior of such electrodes has been compared with conventional carbon paste electrode (CPE) and thoroughly evaluated with respected to the electrochemistry of some biological molecules. In all cases, CNFPE provide better reversibility with substantial decreased overpotential, better defined peak shape, and higher sensitivity compared with CPE. In addition, CNFPE and CPE were employed as H₂O₂ and NADH probes. The obtained experimental results further demonstrated remarkable electrochemical advantages of CNFPE compared with CPE for electroanalytical applications.2) The PD molecules were assembled on the surface of ordered mesoporous carbon through spontaneous adsorption modified glassy carbon electrode (PD/OMC/GCE). Electrochemical behaviors of the resulting electrode were investigated thoroughly with cyclic voltammetry, we studied the kinetics of the catalytic reaction and the catalytic reaction rate constant (k_h) for NADH of PD/OMC/GCE in comparison with PD/GCE. The catalytic reaction rate constant (k_h) of PD/OMC/GCE was calculated to be about 482 times larger than that of PD/GCE. Based on the results, a new NADH sensor was successfully established using the PD/OMC/GCE. Under a lower operation potential of -0.1 V, NADH could be detected linearly up to a concentration of 350μM with a lower detection limit of 0.98μM (S/N=3) as well as a high sensitivity of 5.763μA/mM.