Miniature amperometric self-powered continuous glucose sensor with linear response.

Continuous glucose measurement has improved the treatment of type 1 diabetes and is typically provided by externally powered transcutaneous amperometric sensors. Self-powered glucose sensors (SPGSs) could provide an improvement over these conventionally powered devices, especially for fully implanted long-term applications where implanted power sources are problematic. Toward this end, we describe a robust SPGS that may be built from four simple components: (1) a low-potential, wired glucose oxidase anode; (2) a Pt/C cathode; (3) an overlying glucose flux-limiting membrane; and (4) a resistor bridging the anode and cathode. In vitro evaluation showed that the sensor output is linear over physiologic glucose concentrations (2-30 mM), even at low O(2) concentrations. Output was independent of the connecting resistor values over the range from 0 to 10 MΩ. The output was also stable over 60 days of continuous in vitro operation at 37 °C in 30 mM glucose. A 5-day trial in a volunteer demonstrated that the performance of the device was virtually identical to that of a conventional amperometric sensor. Thus, this SPGS is an attractive alternative to conventionally powered devices, especially for fully implanted long-term applications.