FRACTURED CARBON FIBER-BASED BIOSENSOR FOR GLUCOSE

A microsensor for glucose was constructed using DuPont E120 fibers, wh ich exhibit extensive fracturing upon severe anodic pretreatment. The fracturing is accompanied by an increase in the electrochemical surfac e area of several orders of magnitude, which is exploited here in the design of a microsensor. Following fracture, the fibers were platinize d to enhance their ability to detect enzymatically produced hydrogen p eroxide, and glucose oxidase was immobilized at the surface of the fib er in polypyrrole. When operated amperometrically in flow injection an alysis, the treated electrodes showed a linear response to injected gl ucose concentration up to 10 mM, with an observed K-m' near 20 mM. The sensors were found to be stable for up to 2 months when stored dry at 4 degrees C.