Amperometric biosensors for glucose based on carbon paste modified electrodes

The modification of carbon-paste electrodes by incorporation of the enzyme glucose oxidase (GOD) is described. The resulting probes can be operated as amperometric glucose sensors in the presence or absence of a mediator (1,1'-dimethylferrocene) mixed into the paste. Extended linear calibration ranges have been obtained up to 90 and 5OmM glucose respectively. The electrode responses were rapid, reaching steady-state values within 30-40 sec. Advantages of using a GOD-paste formulation are suggested. Plasma glucose assays were correlated with spectrophotometric determinations based on glucose oxidase (y = 1.07x - 0.16, r = 0.973, n = 17).