PROTOTYPE, SOLID-PHASE, GLUCOSE BIOSENSOR

A single-shot reagentless biosensor for the amperometric determination of glucose is described. The device has been produced in a novel dual -electrode configuration, whereby the working and reference/counter el ectrodes are printed alongside one another in a disposable format. The biosensor is based on a cobalt phthalocyanine-containing screen-print ed carbon electrode coated with cellulose acetate and glucose oxidase (GOD). The organometallic redox mediator permits the detection of GOD- evolved H2O2 at markedly reduced (< 0.5 V, Ag/AgCl) overvoltages. The selectivity is further enhanced by the production of a solvent-cast, H 2O2-permeable film directly over the sensor assembly, serving to scree n out interferents and electrode-fouling agents. Voltammetry and amper ometry have been used to optimize the sensor's analytical performance and SEM to investigate the efficacy of producing the chemical and biol ogical layers.