Glucose sensing, photocatalytic and antibacterial properties of graphene-ZnO nanoparticle hybrids

A simple and efficient approach was developed to uniformly decorate graphene nanosheets with zinc oxide (ZnO) nanoparticles. A single source precursor, zinc benzoate dihydrazinate complex, has been used for the in situ generation of ZnO nanoparticles onto graphene at a relatively low temperature, 200 degrees C. Physico chemical analyses such as X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy revealed that ZnO nanoparticles were finely dispersed on the surface of graphene. ZnO-graphene hybrids were further characterized by Raman spectroscopy and ultraviolet visible spectroscopy and room-temperature photoluminescence. The materials exhibited excellent photocatalytic activity as evident from the degradation of methylene blue in ethanol under UV irradiation. An electrochemical glucose biosensor was fabricated by immobilization of glucose oxidase on the ZnO-graphene hybrids. This biosensor showed improved sensitivity towards glucose as compared to graphene. Also, the hybrids showed significant antibacterial activity against E. coli, gram negative bacteria. This simple and economical preparation strategy may be extended for the preparation of other graphene-based hybrids. (C) 2012 Elsevier Ltd. All rights reserved.