Differential pulse voltammetry determination of ascorbic acid with ferrocene-L-cysteine self-assembled supramolecular film modified electrode

摘要

A supramolecular film containing ferrocene (Fc) has been fabricated on L-cysteine self-assembled monolayers film modified gold electrode by electrostatic adsorption. ATR-FTIR, SEM, cyclic voltammetry (CV), and chronocoulometry (CC) were used to determine the electrochemical properties of the supramolecular film. One reversible redox couple was observed in the pH range of 5.1-9.5, which was attributed to one-electron electrochemical process of Fc, with diffusion coefficient of 1.01 x 10~(-7) cm~(-2) s~(-1). The supramolecular film showed good catalytic activity for the oxidation of ascorbic acid (AA). The catalytic current of AA versus its concentration had a good linearity in the range of 1.0 x 10~(-6) to 5.0 x 10~(-4) mol l~(-1), with the correlation coefficient of 0.9986 by differential pulse voltammetry (DPV) and detection limit of 2.0 x 10~(-7) mol 1~(-1). It was used for the determination of AA in practical medicine with a sensitive and accurate result.