Enzyme-free glucose sensors with channels composed of necked ZnO nanoparticles on plastic

Abstract

In this study, enzyme-free glucose sensors with channels composed of necked zinc oxide (ZnO) nanoparticles (NPs) are constructed on a plastic substrate, and their sensing characteristics are examined. When a phosphate buffer solution (PBS) of lower pH than the isoelectric point of ZnO is adsorbed on the necked ZnO NP channels, the current increases remarkably in magnitude at a bias voltage of 10 V compared with ZnO NP channels without the adsorption of PBS. The current decreases in magnitude with increasing number of moles of added glucose. When 2.5 x 10(-12) moles of glucose are adsorbed on the PBS-adsorbed channels, the current in the channels at 10 V decreases in magnitude from 4.7 mu A to 600 nA. The enzyme-free glucose sensors can detect 5 x 10(-13) moles of glucose in air at room temperature. (C) 2011 Elsevier B.V. All rights reserved.