Glucose Sensor Based on Glucose Oxidase Immobilized by Zirconium Phosphate

Amperometric glucose sensors were fabricated using glucose oxidase (GOx) entrapped in zirconium hydrogenphosphate (ZrP), and their performance was evaluated. Reportedly, α-ZrP is one of the candidates that are expected to improve the stability of enzymes immobilized on solid surfaces.1,2 We intercalated GOxs into ZrP (GOx/ZrP), cast the GOx/ZrP suspension in polyvinylalcohol on a platinum electrode, and dried it in a vacuum oven. The morphological layered structure was investigated by scanning electron microscopy. The enzymatic activities, which were determined by open-circuit potentiometric technique, reached the highest when GOxs were immobilized in ZrP at ca. pH 5. In vitro tests showed good linear responses in the 0 - 25 mM range and the sensitivity of 0.14 nA mM-1 at 0.4 V vs. Ag/AgCl. The sensors, as made, were stable for more than 3 days within a limited deterioration.