Green Synthesis of Copper Oxide Nanoparticles using Dolichandrone falcata (Wall.ex DC.) Seem. Leaf Extract and Assessment of Antioxidant, Antimicrobial, Anti-diabetic and Anticancer Potentials.

Phyto-synthesis of Copper Oxide Nanoparticles (CuO NPs) was carried out using Dolichandrone falcata leaves. The NPs were characterised using Ultraviolet-Visible spectroscopy (UV), UV-Vis diffuse reflectance spectroscopy (UV-DRS), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and dynamic light scattering (DLS). The synthesised CuO NPs UV-Vis spectra revealed that a high absorption peak at 380 nm with optical band gap was 2.8 eV. The appearance of distinctive peaks in XRD pattern verified that CuO NPs were crystalline. Particle size distribution (DLS) revealed the average particle size 222 nm with Polydispersity Index (PDI) value is 0.348. The antibacterial ability of the synthesized CuO NPs was then investigated against major pathogens, including Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). Antioxidant activity against DPPH 61.10% ± 0.90 IC was 273.56 μg/mL, HO 64.36 ± 0.61% IC was 145.43 μg/mL and metal chelating activity 68.20% ± 0.91 with IC value 150.50 µg/mL. Anti-diabetic activity of α-amylase inhibition 75.30% ± 0.59 with IC value 725.32 µg/mL and α-glucosidase inhibition 73.21% ± 0.45 with IC value 540.40 µg/mL. Furthermore, the nanoparticle demonstrated anticancer effects with an IC of 156.26 µg/mL against the skin cancer cell line A431.