Application Of Graphene Oxide Modified Electrode In Bioelectroanalysis

The mediator on the eletrode surface could control the electrochemical reaction rate of target substance, as a result, it has selective electrocatalytic effect. Because of their structural characteristics and excellent electrocatalytic properties, graphene oxide (GO) have been the focus of CMEs. In this thesis, the GO was used as a main modifiing material and modified on glass carbon elelctrode. As a kind of voltammetric sensor, three works were studied as following:1. Graphene oxide (GO) compounded with Nafion was modified on a glass carbon electrode to fabricating a voltammetric sensor (GO/Nafion/GC). The surface morphology and electrochemical characters of the GO/Nafion/GC were investigated by atomic force microscopy (AFM) and electrochemical techniques. The GO/Nafion/GC was then used as a voltammetric sensor in investigating the electrochemistry of Norfloxacin (NFX). The results indicate that it exhibited efficiently electrocatalytic oxidation for NFX with relatively high sensitivity, stability and reproducibility. Under the physiological and optimum experimental conditions, the peak currents of NFX were linear relationship the concentrations in the range of5.0×10-8mol L-1～7.0×10-6mol L-1with a detect limit of5.0×10-8mol L-1. The proposed method was successfully applied to NFX determination in capsules with satisfactory results.2. Similarly, the GO/Nafion/GC was successfully used in simultaneous determination of Epinephrine and Uric Acid. Under the optimum experimental conditions, this sensor revealed good linear response for epinephrine and uric acid in the range of1.1×10-7mol L-1-9.0×10-6mol L-1and1.0×10-7mol L-1～9.0×10-6mol L-1respectively. The detect limits wre5.0×10-8mol L-1for epinephrine and8.0×10-8mol L-1for uric acid. Using proposed method, epinephrine and uric acid in human blood serum were determined with satisfactory results.3. A graphene oxide (GO) compounded with ionic liquid was modified on a glass carbon electrode and the modified electrode was firstly used as a voltammetric sensor in detecting maltol. The results indicate that this sensor exhibited efficiently electrocatalytic oxidation for maltol with relatively high sensitivity, stability and reproducibility. Under the physiological and optimum experimental conditions, this sensor revealed good linear response for maltol in the range of1.0×10-6～1.0×10-4mol L-1with a detect limit of5.0×10-7mol L-1. The proposed method was successfully applied to maltol determination in beer A. beer B and white spirits with satisfactory results.