The work involves the design and testing of new enzyme-based amperometric glucose sensors. Electrical communication between the flavin redox centers of glucose oxidase and an electrode is achieved via a network of donor-acceptor relays chemically bound to a highly flexible, insoluble, high molecular weight polymer. Improvements in stability and selectivity will be pursued through the use of protective polymer coatings and novel enzyme immobilization procedures. The optimized sensors should have widespread technological applications in areas such as the clinical laboratory, veterinary health care, the research laboratory, and the food industry. With the use of protective polymer coatings to prevent fouling of the sensor in biological fluids and electron transfer mediators which are covalently attached to an insoluble polymer to prevent their diffusion away from the electrode, the development of a reusable in vitro blood glucose monitor (for self-monitoring by diabetic patients) appears feasible. The polymeric relay systems are also amenable to needle-type probes which could be useful for many research applications.Awardee's statement of the potential commercial applications of the research: Multiple-use glucose sensors would be of great value to diabetic patients due to the lower cost of such devices (compared with the disposable "strip" or electrode technology presently available). The potential market of the multiple-use glucose sensors is clearly very large. In addition, highly stable in situ probes would be extremely useful for many research and industrial applications.National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)