Preparation And Application Of Carbon Nanotubes And Graphene Oxide Modified Electrode

Because of the unique advantages in selectivity and sensitivity, chemical modified electrode plays an important part in field of electroanalysis. As nanometersized allotropes of carbon, carbon nanotubes (CNT) and grapheme oxide (GO) have excellent performances such as conductivity, specific surface area, electro-catalysis, low cost. In this thesis, we have prepared some modified electrodes based on CNT or GO and some work was done as below:(1) A novel voltammetric sensor, based on singlewalled carbon nanotubes (SWNT) dispersed in Nafion and modified glassy carbon electrode (GCE), was fabricated and used to determine the trace amounts of dihydromyricetin (DMY). The electrochemical behavior of DMY at this sensor was investigated in0.1mol/L sulfuric acid solution+0.1mol/L NaCl by cyclic voltammetry and squarewave voltammetry. Compared with bare GCE, the electrode presented an excellent response of DMY through an adsorption-controlled quasi-reversible process. Under the optimum conditions, the response peak currents were linear relationship with the DMY concentrations in the range of1.0×10-7-1.0×10-5mol/L with a detection limit of9×10-8mol/L. Based on this voltammetric sensor, a simple and sensitive electroanalytical method for DMY was proposed and applied to quantitative determination of DMY in Ampelopsis grossedentata samples. In addition, the oxidation mechanism was proposed and discussed, which could be a reference for the pharmacological action of DMY in clinical study.(2) Graphene Oxide was prepared as reference, the dispersion of GO and DMF was dipped on surface of GCE to fabricate GO/DMF modified electrode. The electrochemical behavior of tartrazine was studied on the modified electrode in0.2mol/L PBS (pH7.4) by cylicvoltammetry and different purse voltammetry. An irreversible redution peak of tartrazine was present on the modified electrode, and the linear relationship with tartrazine concentrations in the range of6.0×10-8-3.0×10-6mol/L with a detection limit of3.0×10-8mol/L.Based on this voltammetric sensor, tartrazine in "Jia Dele" drink was determined and the reduction mechanism was discussed.(3)We combine the method of dispensing and electropolymerization to prepare poly-AR/GO-Nafion composite film modified electrode, and the electrode was used to determine food additive NO2-in0.1mol/Lsulfuric acid solution by cyclic voltammetry and different purse voltammetry. Under the optimum conditions, the response peak currents were linear relationship with the NO2-concentrations in the range of2×10-6mol/L-1×10-4mol/L with a detection limit of4×10-7mol/L...