Development of an electrode mediated glucose sensor using iridium oxide nanoparticles

Abstract

An optimized thin film of Iridium oxide (IrOx) nanoparticles with the presence of Nafion was used to encapsulate the redox enzyme, glucose oxidase (GOx). The resulting films showed an excellent response towards the detection of glucose in both an oxygenated and deoxygenated environment. It was shown that IrOx nanoparticles are mediating the direct transfer of electrons from GOx, and functioning as 4th generation glucose sensors. These sensors (0.2 to 0.008 cm2 ) demonstrated excellent stability and precision when they were tested for glucose strictly under deoxygenated environments; with a linear response up to 40 mM glucose and a sensitivity of 0.5 ?A/cm2/mM (in< 0.3 ?M of dissolved 0 2). In parallel work, an immobilized enzyme kinetic model was derived and the implication of the IrOx/GOx film properties on the apparent Km was presented. This model was also applied to experimental data to assess the interpretation of the parameter.