Eco-friendly Synthesis of Copper Oxide, Zinc Oxide and Copper Oxide–Zinc Oxide Nanocomposites, and Their Anticancer Applications

Copper oxide nanoparticles (Cu2O/CuO NPs), zinc oxide nanoparticles (ZnO NPs) and Cu2O/CuO–ZnO nanocomposites have been prepared using Alchornea cordifolia leaf extract. The nanoparticles were synthesized using simple hydrothermal technique, followed by oven drying in the temperature range of 80–90 °C. The synthesis was monitored by UV–Vis spectroscopy, which confirmed the formation of the nanoparticles by showing peaks above 350 nm and a red shift was observed in the spectra of the nanocomposite. The structural evaluation of the nanomaterials using Fourier transform infra-red spectroscopy showed the presence of amides on their surface, indicative of their role as capping agents. The X-ray crystallographic studies showed mixed phase of Cu2O/CuO NPs, and a hexagonal wurtzite phase for both the ZnO NPs and the nanocomposites. The elemental composition of the nanomaterials were explored using energy dispersive X-ray spectroscopy which confirmed the presence of the respective metals and oxygen; and a higher percentage of Zn (32.48%) compared to Cu (4.97%), in the nanocomposite. The average size of the nanoparticles in the composites were estimated at 3.54 nm with somewhat monodispersity, whereas the monometallic oxides gave agglomerated particles. The search for improved solution to cancerous growths necessitates the verification of the synthesized nanoparticles against cervical cancer using MTT assay method. In vitro cytotoxicity tests of the nanomaterials on cervical Hela cell lines showed efficacy in the order: Cu2O/CuO–ZnO > ZnO NPs > Cu2O/CuO NPs.