Synthesis of colbalt nanoparticle using algal extract and its antimicrobial potential

Abstract

This research encompasses the study of characterization of cobalt nanoparticles (CoNPs) that synthesized from algal extract of Elodea canadensis as well as the evaluation of its antimicrobial potential. The biocompatible method of using algae extract in the synthesis of CoNPs has received growing interest due to its simplicity, environmental friendliness, and economical benefits. The formation of CoNPs was preliminarily confirmed by change in colour of reaction mixture from light pink to brown within 15 minutes. Maximum absorption peak at 320 nm for algal extract and 450 nm for algal encapsulated CoNPs was obtained under UV-Visible spectroscopy as a result of surface Plasmon absorption of CoNPs. Fourier transform infrared spectroscopy proved that CoNPs was successfully capped with active components from E. canadensis extract since the distinct peaks were observed at 3288.4 cm-1 and 1641.8 cm-1 in both the infrared spectrum of the algal extract and bio-reduced CoNPs. Besides, the morphology of CoNPs in term of shape was observed using both the field emission scanning electron microscopy and field emission transmission electron microscopy. It was observed that the CoNPs had spherical and uniform size with smooth surfaces at 1000 nm magnification. Meanwhile, the X-Ray diffraction displayed several broad peaks at 2θ = 52.37°, 54.21°, and 56.09° with mean crystallite size of 14.022 nm that affirmed the crystalline nature of algal synthesized CoNPs. The stability of CoNPs was measured using Zeta potential with PDI value of 0.344 that implies that synthesized CoNPs are very stable. The antimicrobial potential of synthesized CoNPs was evaluated using disc diffusion assay against Escherichia coli and Bacillus sp.