AMPEROMETRIC GLUCOSE SENSOR WITH TETRATHIAFULVALENE AS AN ELECTRON-TRANSFER MEDIATOR

A glucose oxidase (GOD) electrode with tetrathiafulvalene (TTF) as an electron transfer mediator is described. By means of Nafion, TTF was modified on a glassy carbon (GC) electrode surface, and glucose oxidase was then immobilized on the TTF-Nafion film, forming a GOD-TTF-Nafion enzyme electrode. Characteristics of the sensor are shown by cyclic voltammetry and constant potential measurements. The sensor responds rapidly to glucose, the time required to reach 95% of the steady-state current is less than 60s. The sensor displays a sensitive catalytic current response to glucose and can be operated in a potential range in which the oxidation of common interfering species, such as ascorbic acid and uric acid, does not occur. The sensor is stable for more than 30 days at 4 degrees C and plasma glucose assays were correlated with spectrophotometry (n=10, r=0.995).