Electrochemical Template-Free Synthesis of Nanofibrous Polyaniline Modified Electrode for Ascorbic Acid Determination

Abstract

Electrochemical formation of polyaniline (PANI) modified electrode was performed galvanostatically from aqueous solution of 1.0 mol dm(-3) HCl containing 0.2 mol dm(-3) aniline at current densities ranging from 0.5-3.0 mA cm(-2). The morphology of PANI electrode consisted of highly developed nanofibrous network with electrocatalytic features towards oxidation of ascorbic acid, reflected in increase of the peak current similar to 2.5 times and shift of the oxidation potential by 0.32 V to less positive values. Response of PANI modified electrode was obtained from anodic LSV curves. Current peak potentials decreased with increase of pH with slope of similar to 32 mV pH(-1), indicating two electron charge transfer process with liberation of one proton characteristic of an electrochemical reaction followed by a chemical step.