Nonenzymatic Glucose Sensors of ZnO Nanorods Modified by Au Nanoparticles

Abstract

In this article, the nonenzymatic glucose sensor Au nanoparticles (NPs) adsorbed on ZnO nanorods (NRs) was synthesized onto glass substrate by the hydrothermal method, and Au NPs were deposited on the surface of ZnO NRs via direct-current (dc) sputter system. The morphologies and crystal structures of ZnO and Au/ZnO NRs were investigated by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The Au NPs adsorbed on the ZnO NR (Au/ZnO) electrode exhibited excellent sensitivity and selectivity for glucose detection. Under an applied bias of 0.2 V, the sensitivity of ZnO and Au/ZnO NRs electrodes were 63.4 and $182.96 \mu \text{A}$ /cm $^{{2}}{\cdot }$ mM for linear range at 0–8 mM. In the interference detective section, the electrodes of ZnO and Au/ZnO NRs exhibited excellent selectivity for glucose detection when the test solutions contain various interfering species, such as ascorbic acid and uric acid. It is demonstrated that the nonenzymatic glucose sensor of the Au/ZnO NR electrode is suitable for glucose detection in human blood samples.