PROPERTIES OF POROUS ACTIVATED CARBON ELECTRODE MATERIALS USED AS SENSORS FOR GLUCOSE

Platinized activated carbon electrode (PACE) materials were studied in relation to their use in conjunction with glucose oxidase as amperometric sensors for glucose. Four pretreatments were assessed for their effect on increasing the apparent wetted surface area of the materials and the optimum method was found to involve soaking in ethanol. The oxidation-reduction characteristics of glucose, oxygen and hydrogen peroxide were investigated on bare and glucose oxidase (GOD) loaded electrodes. On the platinized material the optimum potential for the detection of hydrogen peroxide generated from glucose via GOD, with minimum interference from direct oxidation of organics, is 350 mV positive to a saturated calomel reference electrode. The variation of steady-state current with potential was studied for electrodes loaded from a range of concentrations of glucose oxidase solutions. The current due to non-enzymatic oxidation of glucose on PACE material loaded with GOD was about one third of the total current in this system.