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.