Conductive polymer-based modified electrode for total antioxidant capacity determination

A poly(3,4-ethylenedioxythiophene)-modified glassy carbon electrode (PEDOTvx/GCE) was prepared by electropolymerization at different scan rates (v) from a monomer EDOT solution by co-doping with an organic dopant (sodium dodecyl sulphate, SDS) and an inorganic compound (LiClO4). The PEDOTv10/GCE modified electrode, which exhibited the highest surface area, was investigated by cyclic voltammetry (CV) at different scan rates or pHs of electrolyte solution, and by differential pulse voltammetry (DPV). The electrochemical and electroanalytical parameters were expressed using caffeic acid, a reference substance. The new modified electrode was used to estimate the antioxidant activity (AA) in different varieties of wines (white, rose, and red). For all types of wines, a good correlation between AA results obtained by electrochemical and spectrophotometrically FRAP assay was obtained.