Electrochemical characterization of different screen-printed gold electrodes

Voltammetric characterization of electrochemical systems is very important with the aim of optimising a required application. In this case, different gold screen-printed electrodes have been evaluated. Although the use of carbon has widespread, gold is still in the beginning. Two different substrates: polycarbonate and alumina have been evaluated. Differences in morphology are clear when observed by SEM. Potassium ferricyanide, p-aminophenol, indigo carmine, silver nitrate and ferrocene have been chosen as model analytes. Potential scans can be made at scan rates as high as 2000 mV s(-1) which could result very advantageous. Proportionality between peak current and concentration maintains at this scan rate as demonstrated with ferricyanide. Sensitivity is increased and linear dynamic ranges are widened when alternative electrochemical techniques (SWV and ACV) are employed. In the silver system in basic media, catalysis-mediated reduction is only possible on alumina electrodes since the potential window is very narrow in polymeric electrodes. The precision (intra and interelectrode) has been thoroughly evaluated. Reusability is possible since adequate RSDs are obtained when measurements are performed in different drops without cleaning in-between. On the other hand, low cost of fabrication makes disposability of electrodes an advantageous characteristic that avoids tedious cleaning treatments. (C) 2007 Published by Elsevier Ltd.