Study on the electrochemical behavior of catechol at a multiwall carbon nanotubes /poly (3-methylthiophene) modified glassy carbon electrode

The electrochemical behavior of catechol at themultiwall carbon nanotubes (MWNTs)/poly (3-methylthiophene) (P3MT)/glassy carbon electrode (GCE) was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The experimental results suggested the modified electrode combined the advantage of P3MT and MWNTs, they exhibited electrocatalytic effect on the oxidation of catechol, and resulted in enhancement of rate of charge-transfer. In 0.1mol L-1phosphate buffer solution (PBS, pH 6.4), the peak currents of DPV were linear with the catechol concentration in two intervals, viz. 0.2-0.6i­mol L-1and 0.6-1.0i­mol L-1,with the correlation coefficients were 0.9996, 0.9967 mentioned above respectively. The detection limit of catechol can be estimated to be 5 i‚´ 10-8mol L-1 (S/N = 3). The effects of scan rates, pH for the voltammetric behavior and detection of catechol were also discussed.