An eco-friendly biogenic method for the synthesis of nickel oxide nanoparticles (NiONPs) using phytochemically rich Berberis pachyacantha leaf extract (BPL) was established. To achieve this purpose, 80 mL of BPL extract was used as a suitable reducing and capping agent for the synthesis of NiONPs. The synthesis of BPL-based nickel oxide nanoparticles (BPL@NiONPs) was confirmed using different microscopic and spectroscopic techniques: UV Visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), dynamic light scattering (DLS) and scanning electron microscopy (SEM) analysis. Spectroscopically, BPL-NiONPs was found with a pure elemental composition (oxygen and nickel), average size (22.53 nm) and rhombohedral structure with multiple functional groups (-OH group and Ni-O formation) on their surface. In the next step, the BPL extract and BPL@NiONPs were further investigated for various biological activities. As compared to BPL extract, BPL@NiONPs exhibited strong biological activities. BPL@NiONPs showed remarkable antioxidant activities in terms of 2,2-diphenyl-1-picrylhydrazyl (76.08%) and total antioxidant capacity (68.74%). Antibacterial action was found against Pseudomonas aeruginosa (27 mm), Staphylococcus aureus (20 mm) and Escherichia coli (19.67 mm) at 500 µg/mL. While antifungal potentials were shown against Alternaria alternata (81.25%), Fusarium oxysporum (42.86%) and Aspergillus niger (42%) at 1000 µg/mL. Similarly, dose-dependent cytotoxicity response was confirmed against brine shrimp with IC50 value (45.08 µg/mL). Additionally, BPL@NiONPs exhibited stimulatory efficacy by enhancing seed germination rate at low concentrations (31.25 and 62.5 µg/mL). In conclusion, this study depicted that BPL extract has important phytochemicals with remarkable antioxidant activities, which successfully reduced and stabilized the BPL@NiONPs. The overall result of this study suggested that BPL@NiONPs could be used as nanomedicines and nanofertilizers in biomedical and agrarian fields.
Keywords: BPL-NiONPs; Berberis pachyacantha; antimicrobial; antioxidant; cytotoxicity; green synthesis; leaf extract; nano fertilizer; phytotoxicity.