Electrochemical Characterization of Electrodes with Submicrometer Dimensions

The construction and electrochemical characterization of electrodes with submicrometer dimensions (2 nm < r(app) < 1000 nm) is reported. Electrodes are prepared by insulating etched Pt wires with electrophoretic paint, as recently reported by Slevin et al. (Electrochem. Commun. 1999, 1, 282). The voltammetric behavior of these electrodes was evaluated using nine different redox systems; well-defined and stable diffusion-limited responses were obtained in all but two cases. The behavior of these electrodes was investigated in aqueous ferrocenylmethyltrimethylammonium (FcTMA+) solutions in the presence and absence of excess supporting electrolyte to determine the influence of diffusion and migration on molecular transport in the nanometer spatial regime. Our findings indicate that the voltammetric behavior of these electrodes can be described using classical transport theory for r(app) > 10 nm.