Implantable glucose sensor

Two new approaches for construction and testing of a miniature in vivo implantable glucose sensor are described. The first approach is to immobilize glucose oxidase onto a platinum wire, coated with special glass (Corning), and to cover the immobilized enzyme with a thin layer of polymer to prevent large molecules from poisoning the electrode. The second, and more successful, approach is to use the principle of coated wire electrodes by incorporating a quaternary ammonium salt with an insoluble glucose salt and poly(vinyl chloride). Potentiometric measurements were used to test the two electrodes, as well as records of voltage and current responses. Responses of the electrodes to varying glucose concentrations are described. Current work is concerned with the responses of these electrodes to plasma and blood, and in examining interference effects from blood chemicals and electrolytes. Alternative methods for preparation of the coated wire electrodes are under investigation, as is their mechanism of action.