Optimization of carbon electrodes derived from epoxy-based photoresist

In this contribution we report on results from an optimization study of SU-8 photoresist derived carbon electrodes. SU-8 derived carbon tends to be glassy in nature, however, based on the exact pyrolysis strategy and other fabrication parameters employed one can obtain a range of electrical, electrochemical and thermal properties related to the variation of the graphitic content of the thus obtained carbon. Hence, in order to obtain electrodes that emulate or improve upon the performance of commercially available glassy carbon (GC) electrodes, the right choice of pyrolysis conditions, and fabrication parameters such as the polymer patterning method, the nature of the substrate, polymer precursor film thickness and dimensions of the electrodes are all important. Carbon electrodes made employing a variety of pyrolysis times and pyrolysis end temperatures, film thicknesses and substrates are investigated by cyclic voltammetry of a redox probe ([Fe(CN)(6)](4-)), resistance measurements and spectroscopic analysis (Raman and XRD). SU-8 derived carbon electrodes displayed a wide potential stability window even in acidic media comparable to that of commercially available GC electrodes. Finally, these electrodes were applied to the simultaneous detection of traces of Cd(II) and Pb(II) through anodic stripping voltammetry and detection limits as low as 0.7 and 0.8 mu gL(-1) were achieved.