Effects of pretreatments and modifiers on electrochemical properties of carbon paste electrodes

摘要: The electrochemical properties of carbon paste electrodes (CPEs), including unmodified and modified with protein polycations, were investigated by impedance spectroscopy (IS) using ferricyanide ferrocene monocarboxylic acid (FcMA) as redox probes. Various pretreatments applied to the CPE. heterogeneous charge transfer rate constant ferro/ferricyanide couple is enhanced 2 10 times compared that obtained at untreated electrodes. It was found for more suitable are successive cyclic voltammetric scans, cathodization a square wave-like stepping rather than high-potential anodization. However, pretreatment only exhibits slight effect on kinetics FcMA. At CPEs containing modifier, electron depends pH electrolyte solution if used. results can be explained differently charged states caused protonation or deprotonation modifiers in various solutions demonstrate importance electrostatic interaction highly polar species such ferricyanide. different adsorptive behavior FcMA also discussed.