Morphological changes of bacterial cells upon exposure of silver-silver chloride nanoparticles synthesized using Agrimonia pilosa

Abstract

Facile, eco-friendly synthesis of metal nanoparticles has been proposed as a cost effective method. In the present study, we propose the facile synthesis of silver-silver chloride (Ag-AgCl) nanoparticles (NPs) using the medicinally important Agrimonia pilosa plant extract without addition of capping or stabilizing agents. The Ag-AgCl NPs synthesis was observed at 40 °C after 10 min incubation; the synthesis of Ag-AgCl NPs was indicated by color change and confirmed by UV-vis spectroscopic peak at 454 nm. TEM analysis confirmed Ag-AgCl NPs were 10–20 nm in size and spherical, and oval in shape. Elemental composition was determined by energy dispersive X-ray analysis, and crystalline structure was confirmed by X-ray diffraction spectroscopy. Different phytocomponents present in the plant extract were analyzed by Gas Chromatography-Mass spectrometry, and the interaction of biomolecules in reduction process was analyzed by Fourier transform infrared spectroscopy studies. The synthesized Ag-AgCl NPs showed significant antibacterial efficiency, analyzed by well diffusion assay against pathogenic bacteria including Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus saprophyticus, Escherichia coli, Pseudomonas putida. Minimum inhibitory concentration and minimum bactericidal concentration were evaluated by microbroth dilution, and spread plate method, respectively. The possible mechanism of bacterial growth inhibition is due to changes in bacterial cell wall morphology that was studied by FE-SEM analysis.