Glucose nanosensor based on Prussian-blue modified carbon-fiber cone nanoelectrode and an integrated reference electrode

An enzyme nanosensor, based on a carbon fiber cone nanoelectrode modified b y codeposition of Prussian blue (PB) and glucose oxidase (GOD), has been co nstructed. The nanosensor displays a low-potential electrocatalytic detecti on of the enzymatically liberated hydrogen peroxide, along with good reprod ucibility and high selectivity. The dependence of the nanosensor response u pon parameters of the sensor preparation (e.g., amount of GOD, PB depositio n time, Nafion coverage), and upon measurements conditions (e.g., pH, appli ed potential) was evaluated. An operating potential of -0.1 V (vs. Ag/AgCl) yielded the highest selectivity towards glucose, with no interference from ascorbic acid. The lifetime of the nanosensor is more than two weeks. Such miniaturization and analytical performance offer great promise for measure ments of glucose in extremely small volumes.