GREEN SYNTHESIS OF SILVER, ZINC AND COPPER NANOPARTICLES FROM THE AQUEOUS EXTRACT OF TERMINALIA IVORENSIS (A. CHEV.) LEAVES AND THEIR ANTIMICROBIAL ACTIVITIES
| ADEYEMI DAVID1, *, ADELUOLA ADEBOWALE2, JOHNSON OLUWATOSIN1, GIWA MARIAM1, SHONEKAN OMONIKE1
1.Department of Pharmaceutical Chemistry, Faculty of Pharmacy. University of Lagos, Nigeria. 2.Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, University of Lagos, Nigeria. Afr. J Pharm Res Dev; Volume 12(2): 164-171 ; 2020 ABSTRACT In recent years, increasing antibiotic resistance by microbes is posing serious threat to humans as well as the health sector. Nanoparticles have proved to be promising candidate as antimicrobial agents, since their large surface area to volume ratio ensures a broad range of attack on bacterial surface. The current study investigated a rapid, eco-friendly and cost-effective approach to synthesis of metallic (Zn, Ag, Cu) nanoparticles (NPs) from Terminalia ivorensis (TI) aqueous leaf extract. The synthesized NPs were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) analysis. Determination of the antimicrobial activities of the metallic NPs was by agar well diffusion method against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The appearance of the NPs varied from brown to dark green and were predominantly rod shaped, with the size ranging from 95-120 nm as revealed by scanning electron microscope. The UV visible spectra analysis of aqueous AgNO3, ZnSO4 and copper acetate showed λ max at 201, 252 and 251nm respectively., while TI extract showed λmax of 660, 207 and 782 nm for Ag, Zn and Cu NPs respectively. The FT-IR study demonstrated that the aqueous plant extract acted as reducing and stabilizing agent during the synthesis of the NPs. The study revealed that all bacterial species tested showed appreciable level of susceptibility towards the green synthesized AgNP, ZnNP and CuNP. From the antibacterial susceptibility and MIC tests, the AgNP and CuNP produced better antibacterial activities than the ZnNP and the aqueous extracts. Email of correspondence: dadeyemi@unilag.edu.ng; KEYWORDS: Antibacterial activities; Green synthesis; Nanoparticles; Spectroscopy.
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