FABRICATION AND ELECTROCHEMICAL FEATURES OF NEW CARBON BASED INTERDIGITATED ARRAY MICROELECTRODES

A new type of interdigitated array (IDA) microelectrode based on carbon film was developed. A conductive carbon film was prepared on a platinum coated Si wafer by the pyrolysis of 3,4,9,10-perylenetetracarboxylic dianhydride. The IDA microelectrode was fabricated by photolithographic techniques from the carbon/platinum composite film. The IDA electrode had 50 microband pairs. The width of each microband was 3-mu-m with a length of 2 mm, and the gap between two electrode bands was 2-mu-m. The electrode was characterized by cyclic voltammetry with water soluble ferrocene and ruthenium hexa-amine. The potential window without redox species was found to be similar to that of a conventional glassy carbon electrode. The IR drop was negligible in a measurement with 10-mu-M water soluble ferrocene at a moderate scan rate. Generation-collection voltammograms of water soluble ferrocene and ruthenium hexa-amine show clear limiting currents and their response in the negative potential range was superior to that of conventional metal film IDA electrodes.