Morphological tuned preparation of zinc oxide: reduced graphene oxide composites for non-enzymatic fluorescence glucose sensing and enhanced photocatalysis

Zinc oxide: reduced graphene oxide (ZnO:rgo) composites with varying ZnO morphologies have been synthesized towards the application of non-enzymatic fluorescence (FL) glucose sensor and photocatalysis for methylene blue (MB) degradation. The phase structure of ZnO has confirmed by X-ray diffraction studies, and the band gap calculations were done by UV absorption spectra. Scanning electron microscope and Raman spectra revealed the morphological change and the vibrational studies of the prepared samples, respectively. The quenching of the FL emission band of ZnO: rgo composite sample confirmed the transfer of electrons from ZnO to rgo which inhibit the exciton recombination process. The non-enzymatic FL glucose sensing was carried out by the addition of dextrose glucose (D-glucose) into the ZnO: rgo composite solution, which shows strong relationship between glucose concentration and the FL intensity. The photocatalytic studies showed that composite with high surface to volume ratio exhibits a maximum degradation of MB over 93 %. Our combined results ensured that the ZnO: rgo composites with varying morphologies could be an effective system for applications such as FL-based glucose sensing and photocatalytic degradation.