GREEN SYNTHESIS, CHARACTERISATION, AND ANTIMICROBIAL ACTIVITY OF NICKEL OXIDE NANOPARTICLE USING MORINGA OLEIFERA LEAF AQUEOUS EXTRACT

ABSTRACT

The moringa plant has been known and used for years in various ways, especially in treating ailments. In this research, the leaves of this plant were used in the synthesis of nickel oxide nanoparticles. Extraction was carried out using the method known as cold maceration. Phytochemical screening of the aqueous extract of moringa leaves was done using standard methods, and the presence of alkaloids, saponins, eugenols, terpenoids, phenolics, and glycosides was detected. The synthesis of nickel oxide (NiO) nanoparticles from Moringa oleifera, utilising a green synthesis approach, is explored in this study. The synthesised NiO nanoparticle was characterised using ultraviolet-visible (UV-Vis) spectroscopy, attenuated total reflectance- fourier transform infrared radiation (ATR-FTIR), and scanning electron microscopy (SEM). The FTIR analysis data showed the formation of the NiO in the nanoparticles. The UV-visible spectroscopy results identified specific absorption peaks that reflect the optical properties of NiO. The FTIR analysis confirmed the presence of bio-organic chemical groups in the Moringa extract, indicating their role in nanoparticle formation and stabilisation. SEM analysis provided insights into the morphology and size distribution, showing particles with a uniform size. Antimicrobial tests revealed that the NiO nanoparticles exhibited significant inhibitory activity against a range of microorganisms, which include Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative (Escherichia coli and Pseudomonas aeruginosa), as well as some fungi (Candida albicans and Aspergillus niger), highlighting their potential as an effective antibacterial agent with notable bactericidal properties against P. aeruginosa. This suggests their applicability in medical and environmental applications where antimicrobial materials are crucial.