Electrochemical characterization of recessed nanodisk-array electrodes prepared from track-etched membranes

Recessed nanodisk-array electrodes (RNEs) fabricated from track-etched polycarbonate membranes (TEPCMs) having cylindrical nanopores (50 nm in diameter) were characterized using cyclic voltammetry (CV). Such electrodes were prepared by depositing a gold thin film onto a TEPCM via sputtering or thermal evaporation. CV of the RNEs showed the transition from linear to radial diffusion modes of redox-active molecules with decreasing scan rate. The resulting change in maximum faradic current, which is the peak current in a peak-shaped CV and the plateau current in a sigmoidal CV, provides a simple means for calculating the pore length and effective pore density within a RNE. This method permits us to assess the completeness of the seal between a TEPCM and gold film as well as the extent to which air bubbles block the nanopores.