Electrochemical characteristics of an interdigitated microband electrode array of boron-doped diamond film

An microband electrode array (MBEA) of a boron-doped diamond (BDD) film was prepared by using the hot-filament chemical vapor deposition (HF-CVD) technique and microfabrication process with a standard photolithography technique. Electrochemical properties of a single MBEA (S-MBEA) and interdigitated MBEA (I-MBEA) of BDD film were studied by cyclic voltammetry (CV) analysis. Charge transfer characteristics were examined by electrochemical impedance spectra (EIS) analysis. A ferri-ferrocyanide redox system was chosen to act as the probe of one-electron transfer processes. The redox reaction was controlled by linear diffusion-limited transport at S-MBEA and quasi-steady-state non-linear diffusion at I-MBEA. A relation between current limit at I-MBEA and sweep rate was obtained with a correlation coefficient greater than 0.93. Hemispherical diffusion was primary at I-MBEA of BDD surface. There were two time constants for the S-MBEA and one time constant for the I-MBEA in the redox system.