Synthesis, Characterization and Antimicrobial activity of Dioscorea alata plant Extract Mediated Manganese Dioxide Nanoparticles

Abstract

In the field of nanotechnology, metal and metal oxide nanoparticles have attained a great significance due to their unique properties. Manganese dioxide nanoparticles have attracted high attention in recent studies due to its potential applications like antibacterial, antifungal and anti-cancer. In this study synthesis of Manganese dioxide nanoparticles was done using biological/green synthetic method from indigenous ‘Dioscorea alata is a medicinal plant which commonly grows in south West Ethiopia. The synthesized MnO2 nanoparticles were characterized using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), UV- Visible and Fourier Transform Infrared spectroscopy (FTIR). The average crystal size of the synthesized NPs was calculated using the Debye Scherer equation. The average crystal size of MnO2 NP was found to be 16.73nm (1:2 ratio), 9.60 nm (1:1), 16.90 nm (2:1) calcinated, and 7.13 nm (1:2) 5.72 nm(1:1) and 7.76 nm(2:1) uncalcinated MnO2 NPs for green synthesis method. The XRD pattern with sharp peaks describes the crystalline and purity of Manganese dioxide nanoparticles. The FTIR spectrum of Manganese dioxide (Mn-O) nanoparticles absorbs at 557 cm-1 and 547 cm-1 for both calcined and uncalcinated respectively. Furthermore, the antibacterial and antifungal activity of the synthesized MnO2 nanoparticles were evaluated against clinical and standard strains of Escherichia coli, Pseudomonas aeruginosa Staphylococcus aureus and Enterococcus faecalis by disc diffusion method using the suspension of bacteria spread on MH agar. The positive control for antibacterial testing was ciprofloxacin. According to this study, MnO2 nanoparticles synthesized using Dioscorea alata leaf extract showed promising result against both gram- positive and gram-negative bacterial strains with maximum inhibition zone of 17.66nm E. faecalis and 16nm E.coli respectively. The positive control used for antifungal testing was Gentamycin.