Green synthesis of NiO/ZnO nanocomposite using Vitex negundo leaf extract for antibacterial and anti-inflammatory activities

Abstract

The eco-friendly synthesis of Nickel Oxide/Zinc Oxide (NiO/ZnO) nanocomposite nanoparticles (NPs) using Vitex negundo leaf extract offers a sustainable and green approach to developing nanomaterials for biomedical applications. Three different molar ratios were synthesized: F1 (equal proportion of NiO and ZnO), F2 (high zinc, low nickel), and F3 (high nickel, low zinc). XRD analysis confirmed excellent crystallinity, with ZnO particle sizes of 14.35 nm (F1), 15.91 nm (F2), and 22.97 nm (F3), while NiO sizes ranged from 14.11 nm to 15.75 nm. UV-Vis spectroscopy revealed bandgap energies of 2.7 eV (F1), 2.75 eV (F2), and 2.55 eV (F3), highlighting compositional effects. SEM analysis demonstrated sheets morphology with minimal agglomeration, and EDX confirmed elemental composition. The F1 ratio exhibited superior antibacterial performance, showing a 1.5 mm inhibition zone against Staphylococcus aureus and Pseudomonas aeruginosa. Anti-inflammatory studies revealed concentration-dependent inhibition, with F1 achieving the highest inhibition (46.2% at 500 µg), though lower than diclofenac (70.3%). This study highlights the successful synthesis of NiO/ZnO nanocomposites, particularly F1, with significant antibacterial and anti-inflammatory potential, emphasizing the role of eco-friendly methods in advancing biomedical research.