ISFET glucose sensor based on a new principle using the electrolysis of hydrogen peroxide

An ISFET glucose sensor based on a new principle using the electrolysis of hydrogen peroxide, one of the by-products of the oxidation of glucose, and a Pt electrode actuator is proposed and the characteristics investigated. Compared with the conventional ISFET glucose sensor, the proposed sensor shows an improvement of four times the sensitivity, an extension of the dynamic range to 5 mM glucose concentration, and a faster response of 3 min in 10 mM phosphate buffer solution (pH 7.4, 100 mM NaCl). In addition, the baseline of the sensor response can also be checked, so that the influences of drift of the ISFET and pH change in the sample solution can be eliminated. The sensor shows a large dependence on the buffer concentration. When the buffer concentration is changed from 5 to 20 mM, the sensitivity decreases by a factor of four, However, the high sensitivity, 9 mV mM(-1) even in 20 mM buffer concentration, will still allow the sensor to measure glucose concentrations of human blood without the need for dilution.