Electroanalysis of copper species at polypyrrole-modified electrodes bearing alizarin red S ligands

Conducting polymer modified electrodes based on the incorporation of the anionic complexing ligand alizarin red S into polypyrrole (Ppy) film during electropolymerization were applied to the electroanalysis of metal species including Cu⁺ and Cu²⁺. The copper species were readily extracted into the Ppy film electrode containing the complexing ligands and were determined electrochemically. The sensitivity for determination of Cu²⁺ species was significantly better than that for Cu⁺ species at much lower concentrations despite a smaller complex stability, but suffered from a very limited linear region. The results also showed that the ligand-to-metal ratios for complex formation at the Ppy film were concentration dependent.