Enhancements in conductivity and Raman spectroscopy of polypyrrole electropolymerized on electrochemically roughened Au substrates

In this study, gold substrates were first roughened by a triangular-wave oxidation-reduction cycle (ORC) in an aqueous solution containing 0.1 N HCl, and then polypyrrole (PPy) films were electrochemically deposited on the roughened gold substrates. In ORC treatment, Au- and Cl-containing complexes with nanostructure were formed on the surface of gold. The nanocomplexes show a catalytic electroxidation pathway for the polymerization of PPy. The characteristics of PPy deposited on this roughened Au are distinct from those of PPy deposited on the polished Au without further ORC treatment. They include the demonstration of the surface-enhanced Raman scattering effect, a higher conductivity and an increase in oxidation level of the prepared PPy.