Biosynthesis of Manganese Nanoparticles (MnNPs) from Brassica oleraceae (Cabbage leaves) and its Antibacterial Activity

Abstract

Manganese nanoparticles are promising material for various applications such as water remediation, catalytic oxidation reactions, bio sensors, etc for their superior adsorbing, electrochemical, catalytic, magnetic, supercapactive like properties additionally, MnNPs possess significant medicinal values, hence, this research aims at synthesizing MnNPs biogenically, characterize them to explore antibacterial activity. Aqueous cabbage extract was allowed to react with precursor KMnO4 solution to synthesize the MnNPs. Then, MnNPs were characterized by: visual observation, UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX). Finally, agarwell diffusion was employed to study antibacterial activity against human pathogenic bacteria: staphylococcus aureus ATCC 25923, escherichia coli ATCC 25922 and salmonella typhi. Turning of purple color solution to reddish brown after stirring was the indication of the formation of nanoparticles. The formation of MnNPs was confirmed by appearance of sharp peak at 420 nm, the assigned band for MnNPs and the energy absorption band at 6 keV in EDX spectrum. Diffraction pattern of MnNPs revealed polycrystalline type with crystallite size of 10.70 nm. FT-IR result showed the chief biomolecules: flavoniods, alkaloids, proteins present in the extract which acts as reducing agent. FE-SEM confirmed the formation of spherical and ellipsoidal shaped agglomerated MnNPs. Agarwell diffusion method showed zone of inhibition (ZOI) of range 10-13 mm with (gram + ve and gram –ve) bacteria. Cabbage mediated biosynthesis of MnNPs is found simple, ecofriendly. This work revealed the formation of agglomerated MnNPs confirmed from uv-vis spectra and FE-SEM. Chief biomolecules of the extract act as reducing agent and stabilizing agent. Results of agarwell diffusion method depicted MnNPs are promising material for its antibacterial properties.