Nanorod arrays composed of zinc oxide modified with gold nanoparticles and glucose oxidase for enzymatic sensing of glucose

We report on an enzymatic electrochemical glucose biosensor based on the use of zinc oxide nanorods (ZnO NRs) modified with gold nanoparticles (Au-NPs) and arranged in the form of an array. The nanorods were obtained via a hydrothermal method, and the Au-NPs were synthesized by photo-reduction. The surface of the nanoarrays was then modified with Au-NPs via electrostatic self-assembly. GOx was immobilized onto the surface of Au-NPs modified ZnO nanoarrays by electrostatic adsorption. The performance of the resulting glucose biosensors were investigated by cyclic voltammetry and amperometry. Compared to biosensors based on ZnO nanoarrays without Au-NPs, the ones described here exhibit a higher sensitivity (43.7 nA cm−2 mM−1) and a lower Kapp,M (0.78 mM). It is obvious, therefore, that the Au-NPs play an important role with respect to the performance of this biosensor.