In the proposed program, sensors based on electrochemical principles would be developed using chemically modified electrode technology. The development of amperometric, immobilized enzyme electrodes with electron transfer from the enzyme mediated by a polymer-immobilized redox couple on a metallic electrode is recommended. Selectivity will be afforded by use of glucose oxidase as the primary reactant with glucose. Sensor reliability will be optimized by the selection of redox couples to provide fast regeneration of reduced glucose oxidase, and by immobilization techniques and membranes which exclude large biological molecules. Sensors of the type envisioned here can be made quite small, and would require a minimum of low-power electronics for operation.Initial work at SumX has demonstrated the use of an electroactive polymer modified metal electrode to mediate glucose oxidation by glucose oxidase. The Phase I objectives will be to determine if truly rugged sensors of this type can be constructed of polymer-immobilized redox couples on metallic electrodes and can be operated for extended times in physiological media.National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMSD)