Graphene-copper oxide nanocomposite with intrinsic peroxidase activity for enhancement of chemiluminescence signals and its application for detection of Bisphenol-A

Graphene-copper(II) oxide (G-CuO) nanocomposite was synthesized for the first time by simple and rapid microwave assisted co-precipitation method using copper acetate as a precursor. Synthesized G-CuO nanocomposite showed the characteristic Raman and Fourier transform infrared peaks of CuO below 700 cm−1. Characteristic crystalline peaks of CuO corresponding to monoclinic symmetry was observed in X-ray diffraction analysis. Nanocomposite with quasi-spherical morphology was observed in transmission electron microscopic analysis. Nanocatalytic activity of G-CuO nanocomposite was examined by its efficiency to improve the signals of luminol-H2O2 chemiluminescence (CL) reaction. G-CuO nanocomposite enhanced the signals of CL reaction by 280 times higher than control. Enhancement in CL signals is attributed to intrinsic peroxidase like activity of G-CuO nanocomposite on H2O2 breakdown to OH− and O2 ions. Formation of radicals and ions by nanocatalytic mechanism was hypothesized and confirmed by trolox assay. G-CuO has higher intrinsic peroxidase like activity than bare copper oxide (CuO) nanoparticles by 23 times. G-CuO nanocomposite can be a better alternative to peroxidases and nanomaterials which are used to enhance the CL signals. Analytical application of enhanced luminol-H2O2 CL reaction was applied for detection of Bisphenol-A (BPA) in feeding bottles and polycarbonate water bottles. Proposed enhanced CL method has linearity in the range 10,000-1 ng/mL with limit of detection of 0.55 ng/mL and limit of quantification of 8.3 ng/mL. Intrinsic peroxidase like activity of synthesized G-CuO can have wide application in nanocatalysis and analytical chemistry for the development of CL based analytical and biomedical kits, sensors, and assays.