OXIDATION OF GLUCOSE AT ELECTRODEPOSITED PLATINUM-ELECTRODES IN ALKALINE-SOLUTION

The oxidation of glucose has been studied at electrodeposited platinum electrodes in 0.1 mol dm-3 NaOH over a range of glucose concentrations using the electrochemical quartz crystal microbalance (EQCM). The influence of glucose on the mass response is less than in acid media and poisoning appears to be less of a problem in the lower potential ranges. The mass shows an increase coincident with the second oxidation peak on an anodic scan that is similar to that observed in acid solutions and is attributed to the replacement of partially oxidised glucose species by fresh glucose molecules. At higher glucose concentrations (0.1 mol dm-3) the mass response reveals that the oxidation of the electrode surface is inhibited and only occurs at potentials several hundred millivolts more positive than its value in background electrolyte.