Glucose ENFET doped with MnO2 powder

In this study, a glucose-sensitive enzyme field-effect transistor (ENFET) c oimmobilized with glucose oxidase (GOD) and manganese dioxide (MnO2) have b een investigated. The biomembrane of the ENFET was immobilized on the amorp hous tin oxide/indium tin oxide glass structure extended sensitive gate, wh ich used as a disposable transducer of a glucose biosensor. MnO2 was used a s a catalyst which can catalyze the hydrogen peroxide and produced H2O and O-2. Coimmobilizaion of glucose oxidase and manganese dioxide was found to be useful for extending the dynamic measured range of glucose concentration to 360 mg/dl (eg. 20 mM). The result shows that the dynamic range of the o utput signal is strongly dependent on pH value of measuring environments, a nd the measurement in the alkali buffer solutions shows a higher response a nd wider dynamic range. Additionally, the different immobilized layers of M nO2 have been studied. The MnO2, which be immobilized in outer cross-linkin g layer of bovine serum albumin, shows better results than immobilized in G OD layer or gultaraldehyde covalent layer. (C) 2001 Elsevier Science B.V. A ll rights reserved.