Nanostructured glucose-oxidase immobilized SnO2 thin films for glucose sensing

Polycrystalline rutile films of SnO2 (similar to 1500 angstrom )were deposited on Al2O3. Film imaging showed regular ellipsoidal nanostructured growth. Different concentrations (1000-3000 U) of glucose oxidase (GOx) were immobilized on SnO2 surface. Upon interaction with various glucose concentrations (65-300 mg/dl), films showed pronounced change in their sheet resistance with recovery and repeatability. Nanostructured SnO2 surfaces probably enhance adsorption of oxygen moieties. These convert to their ions by extracting electron/s from the conduction band of SnO2, which further interacts with H+, formed during the GOx-glucose interaction. This releases the trapped electron to the conduction band of SnO2, justifying its role as a catalyst. (C) 2011 American Institute of Physics. [doi:10.1063/1.3555460]