Electrochemical studies of amaranth at surfactant modified carbon paste electrode: A cyclic voltammetry

Electrochemical reduction of amaranth has been studied at carbon paste electrode in sulphuric acid media using cyclic voltammetric technique. The adsorption of cetyl trimethyl ammonium bromide (CTAB) on a carbon paste electrode was investigated. The results showed that CTAB exhibited two types of adsorptive behavior at a carbon paste electrode at different concentration ranges: monomer adsorption at concentrations below 10 mu L and monolayer adsorption at concentrations higher than 40 mu L CTAB. In the monomer adsorption range, the adsorption of CTAB could effectively reduce the charge transfer resistance and increase the charge transfer rate. However, the surface properties of the carbon paste electrode hardly changed. On the formation of a CTAB monolayer, the structure of the electrode interface changed significantly and the electrode/solution interface. The same mechanism has been proposed for SDS.