Electrocatalysis and sensitive determination of cysteine at poly(3,4-ethylenedioxythiophene)-modified screen-printed electrodes

The electrocatalytic oxidation of cysteine at screen-printed electrode (SPE) modified with electrogenerated poly(3,4-ethylenedioxythiophene) film (PEDOT) was investigated. Cyclic voltammetric studies showed that the SPE/PEDOT electrode lowers the overpotentials and improves electrochemical behavior of cysteine oxidation, as compared to the bare SPE. The catalytic oxidation responses were studied and the reaction mechanisms were discussed. Excellent analytical features, including high sensitivity, low detection limit and satisfactory dynamic range, were achieved by flow-injection amperometry under optimized conditions.