In vitro antioxidant activities of copper mixed oxide (CuO/Cu2O) nanoparticles produced from the leaves of Phoenix dactylifera L

Biosynthesis of antioxidant nanoparticles using plant extracts is a simple, rapid, environmentally friendly, and cost-effective approach. In this study, in vitro antioxidant copper mixed oxide nanoparticles (CuO/Cu 2 O) were prepared from the alcoholic extract of Phoenix Dactylifera L. and different aqueous concentrations of CuSO 4 ·5H 2 O. The composition, crystallinity, morphology, and particle size of CuO/Cu 2 O NPs were tuned by increasing the CuSO 4 ·5H 2 O concentration from 4 to 10 mM. Ultraviolet–visible (UV–Vis) and Fourier-transform infrared (FTIR) spectroscopy confirmed the reduction of CuSO 4 ·5H 2 O and the formation of the CuO/Cu 2 O NPs. X-ray diffraction (XRD) confirmed the crystalline nature of the CuO/Cu 2 O NPs with a crystallite size varying from 18 to 35 nm. Scanning electron micrographs (SEM) showed that the CuO/Cu 2 O NPs have a spherical morphology with particle sizes ranging from 25 to 100 nm. The best antioxidant CuO/Cu 2 O NPs have a phase ratio of about 1:1 CuO/Cu 2 O with a half-maximal inhibitory concentration (IC 50 ) of 0.39 mg/ml, an iron-containing reducing antioxidant power (FRAP) of 432 mg EFeSO 4 /100 mg NPs, and a total antioxidant capacity (TAC) of 65 mg EAA/gNPs. The results suggest that the synthesized CuO/Cu 2 O NPs are excellent antioxidants for therapeutic applications.