Journal of Electroanalytical Chemistry, Vol.365, No.1-2, 79-86, 1994
Frequency-Dependent Capacitance of Microelectrode Arrays and Characterization of the Metal-Polymer Interface
The seal between the metal and Tefzel in microband electrodes and arrays is described. The high apparent capacitance of these electrodes suggests that the solution penetrates between the metal and Tefzel. The solution penetrates most deeply into platinum electrodes, while gold and nickel electrodes have relatively good seals. The depth of penetration for platinum electrodes is estimated from capacitance data to be as large as 1.2 mm; however, the gap depth is highly variable. By coulometry of a ferricyanide solution contained in the gaps, the gap width is estimated as 1-2 mum. Platinum electrodes with an excellent seal to Tefzel can be prepared if the platinum foil is sputter coated with a thin layer of gold before the electrode is constructed.
Keywords:CARBON-FIBER MICROELECTRODES;ULTRAMICROELECTRODE ENSEMBLES;SMALL ELECTRODES;FABRICATION;FILMS;VOLTAMMETRY;PLATINUM;ADHESION