Characterization and application of bismuth-film modified carbon film electrodes

Bismuth film electrodes, formed by electrochemical deposition on carbon film resistor electrode substrates at constant applied potential, by potential cycling or at constant applied current have been investigated for the first time. The electrochemical behaviour of the films was characterised by cyclic voltammetry and electrochemical impedance spectroscopy and they were applied to the determination of Zn, Cd, and Pb by square-wave anodic stripping voltammetry. The highest sensitivities coupled with nanomolar detection limits were achieved at bismuth films formed at constant potential; however, in situ deposited bismuth films exhibited better reproducibility. Future application as small, short-term-use sensors is indicated.