ANTIMICROBIAL PROPERTIES OF DOPED AND UNDOPED PLANT-BASED SYNTHESIZED ZINC OXIDE AND SILVER NANOPARTICLES

Abstract

The process for the development of a reliable and ecofriendly metallic nanoparticle (NP) is an important step in biomedical application of nano technology. Zinc oxide nanoparticle (ZnONps) and silver nanoparticle (AgNps) is gaining attention in nanobiomedical due to their biocompatibility and antimicrobial activities. Therefore this study is aimed at evaluating the ecological synthesis of zinc oxide, silver doped silver and zinc oxide nanoparticle plus their antimicrobial properties. The green synthesis of ZnONps and AgNps was done using Senna occiddentalis. The green synthesized ZnONps and AgNps nanoparticles were characterized using UV-Visible spectroscopy, fourier transforms infra-red spectroscopy, Energy dispersive spectrum (EDS) and transmission microscope analysis (TEM). The NPs were tested for antimicrobial properties using agar well diffusion assays. The results indicated that the ZnONps and Ag NPs synthesized has particle size of 52.50 nm with intensity of 13.85 % at 393 nm wavelength, while AgNps were distributed at 83.40nm with intensity of 14 % at 331 nm wavelength and the particle size are 52.50 nm and 393 nm in wavelength, while silver nanoparticle were distributed around 83.40nm with intensity of 14 % and 331nm in wavelength. The surface morphology of the AgNps and ZnONps using TEM showed the presence of highly aggregation of spherical and irregular shape respectively. The EDS Spectrum of the AgNps showed optical absorption band peak at 3.0-3.5 KeV while ZnONps was at 1.0, 8.8, 9.8 KeV for mpH 7, 10, 11 and 12. The FT-IR spectral of bio-synthesized AgNp while ZnONps showed signal at 2893 and 3493 cm-1 corresponding to the –O-H stretch. The antimicrobial activity of AgNps produced dose dependent increase inhibition on Streptococcus pyogenes, Escherichia coli, Staphylococcus auerus and Pseudomonas aeruginosa, the activity of doped zinc and silver nanoparticles produced inhibition of S. pyogenes only amongst the tested organisms, however, ZnONps showed minimal antibacterial activities on S.aureus alone. However, it can be concluded that Senna occidentalis reduced Zinc acetate and Silver nitrate to Zinc oxide and silver ion respectively which provided minimum inhibitory effect on the selected microorganisms.