Voltammetric Resolution of Ascorbic Acid and Dopamine at Conducting Polymer Electrodes

Abstract

Abstract Electrochemical behavior of dopamine and ascorbic acid binary mixture was examined by cyclic voltammetry and the analysis of a each component was performed by differential pulse voltammetry. The electrochemical behavior of these molecules on poly-3-methylthiophene, polypyrrole, polyaniline electrodes were compared. The effects of electrolyte type and its pH, and the film thickness on the voltammetric resolution of these molecules were systematically examined. At all the modified electrodes both dopamine and ascorbic acid peaks shifted their positions to more negative potentials with increasing pH, difference between the positions remaining almost constant. Type of electrolyte seems to have an effect on ascorbic acid peak only at the poly-3-methylthiophene electrode. The effect of increasing film thickness was to observe increased peak heights.