The role of oxygen functionalities and edge plane sites on screen-printed carbon electrodes for simultaneous determination of dopamine, uric acid and ascorbic acid

The role of oxygen functionalities and edge plane sites on disposable screen-printed carbon electrodes (SPCE) was evaluated for simultaneous determination of dopamine, uric acid and ascorbic acid in this study. Both electrochemically preanodized and oxygen plasma treated SPCEs were adopted for the purpose of partially differentiating these two effects. Raman and XPS analyses verify that different treatment can indeed induce different surface characteristics. The electrocatalytic activity thereby increases by the substantial increase in surface bound carbon-oxygen functional groups and/or the generation of edge plane sites through surface reorientation. Possible mechanism is proposed to explain the voltammetric behavior. The peaks for dopamine, uric acid and ascorbic acid are especially well-resolved from each other at the electrochemically preanodized SPCE and simultaneous detection at neutral pH can thus be obtained by this simple approach. (c) 2008 Elsevier B.V. All rights reserved.