Electroanalysis of metal species at polypyrrole-modified electrodes

Conducting-polymer-modified electrodes based on the incorporation of two anionic ligands, namely bathophenanthroline disulfonate and bathocuproine disulfonate, into polypyrrole film during electropolymerization were found to show sensitivity to copper species (both Cu⁺ and Cu²⁺ ions). The copper species were readily extracted into the polypyrrole film electrode containing the complexing ligands. The electrochemical reaction of the incorporated copper complex resulted in a measurable square-wave voltammetric peak current, which was found to be related to the logarithm of copper concentrations. Reproducibility of the determination of copper species by the ligand-incorporated polypyrrole-modified electrodes was around ± 11% RSD and the detection limit was estimated to be about 2 μM.