Long-term performance of a rechargeable glucose electrode in vitro.

A rechargeable glucose sensor now under development performed satisfactorily for over eight months at 25 degrees C and over 90 days at 37 degrees C without recharging. A prototype sensor was operated through three recharge cycles, which increased the life of the sensor more than two months. This demonstrates the potential for reducing the frequency of surgical replacements. Earlier work utilized three forms of carbon upon which glucose oxidase was immobilized. Recent work reported herein demonstrates that the longer-performing sensor is realized with ultra-low-temperature isotropic (ULTI) carbon powder. Due to its fine particle size, the ULTI carbon with immobilized enzyme acts as a liquid suspension. The sensor is stable and there is no detectable degradation of the sensor components from one recharge cycle to the next.