Phytogenic Synthesis of Copper Oxide Nanoparticles Using <i>Cucumis Sativus</i> Extract: Antibacterial, Wound Healing, and Photocatalytic Activities

The current study discusses the eco-friendly synthesis of copper oxide nanoparticles (CuO NPs) using an aqueous extract of Cucumis Sativus (cucumber) as the stabilizing agent. After characterization using spectroscopic techniques such as UV/Vis spectroscopy, FTIR, SEM, EDX, and XRD, CuO NPs were evaluated for antibacterial, wound-healing, and photocatalytic activity. UV/Vis analysis revealed a peak at 290 nm due to surface plasmon resonance (SPR), with an energy band gap of 4.18 eV. The successful synthesis of CuO NPs was confirmed from the FTIR band (594 cm^-1) due to the copper-oxygen bond vibrations. SEM analysis revealed hexagonal plate-like and irregularly shaped NPs. Energy dispersive x-ray spectroscopy revealed Cu (43.83%) and O (28.44%) as the main elements. x-ray diffraction showed a monoclinic phase with a face-centred cubic structure and a mean crystallite size of 29.55 nm. Gram-positive (B. subtilis) and Gram-negative (E. coli) bacterial strains are more susceptible to CuO NPs than the cucumber extract. Both neomycin (15 mg/kg) and CuO NPs (5 mg/kg) healed the wound quickly. CuO NPs under solar irradiation efficiently degraded dyes such as methylene blue (94.4%), methyl orange (91.07%), and congo red (79.31%) within two hours. Thus, CuO NPs could be effectively used for biomedical and environmental applications.