Improved voltammetric peak separation and sensitivity of uric acid and ascorbic acid at nanoplatelets of graphitic oxide

In this study, much improved voltammetric peak separation and sensitivity of uric acid and ascorbic acid was observed at a screen-printed carbon electrode modified with nanoplatelets of graphitic oxide (GO). Electrochemical sensing of uric acid and ascorbic acid was further used to explore the role of oxygen functionalities and edge plane sites on electrocatalysis at GO. We successfully apply a microwave-assisted hydrothermal elimination method to remove the oxygen-containing functional groups from the GO surface. The edge plane on GO can be retained and the density of oxygen-containing functional groups can be easily controlled by varying the microwave treatment temperature. Using this platform, such discrimination to peak separation is attributed to the very distinct behavior of uric acid and ascorbic acid to form hydrogen bonds with oxo-surface groups (especially COOH group) at GO.