We have developed an amperometric glucose sensor whose electrodes are coated with a four-layered membrane: 3-aminopropyltriethoxysilane (gamma-APTES), Nafion, glucose oxidase (GOX), and perfluorocarbon polymer (PFCP). Tests demonstrate the sensor's ability to accurately and successively determine glucose concentrations ranging from 2.8 to 167 mM, over a 66 day period with no increase in response time, while remaining imperviousness to the effects of interference species (2.8 mM ascorbic acid, 0.3 mM uric acid, 0.3 mM p-acetaminophen). Furthermore, tests on diabetic urine samples showed an excellent correlation coefficient of 0.985 (y=1.04x+4.73, n=30) between sensor results and those of Glucose-Dehydrogenase clinical laboratory analyses.