Electrochemical behaviour of dopamine on the polytheophylline/nafion dual-layer modified glassy carbon electrode

The fabrication and electrochemical characteristics of polytheophylline/Nafion dual-layer modified glassy carbon electrode were investigated, the electrode was applied to the determination of dopamine. In PBS buffer of pH 7.4, a sensitive oxidation peak was observed at 0.30 V with the dual-layer modified glassy carbon electrode. The peak current is proportional to the concentration of dopamine in the range of 1 x 10(-7) similar to 4 x 10(-4) mol/L, the detection limit is 5 x 10(-8) mol/L. The modified electrode has a well-repeatability and can enhance the sensitivity for the determination of dopamine, and repel the interference of ascorbic acid. This electrode has been shown to be suitable for quantitative determination of dopamine.