Green Synthesis of Silver Nanoparticles (AgNPs), Structural Characterization, and their Antibacterial Potential

Abstract

Background In the field of nanotechnology, the metallic nanoparticles are of remarkable interest because of their unique electronic, magnetic, chemical, and mechanical properties. Purpose: In the present work, silver nanoparticles (AgNPs) were synthesized using bio-reduction method. Research Design: Silver nitrate was used as metallic precursor and the extract of Moringa oleifera leaves with different concentrations was used as reducing as well capping agent. The extract exhibited strong potential in rapid reduction of silver ions for the synthesis of silver nanoparticles. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. Results: The absorption SPR peaks appeared in the range of 415 to 439 nm. SEM analysis exhibited that particles were spherical in shape with size distribution range from 10 nm to 25 nm. The synthesized silver nanoparticles were pure crystalline in nature as confirmed by the XRD spectra with average crystallite size 7 nm. In vitro antibacterial activity of the prepared silver nanoparticles colloidal samples as well the extract was studied using different concentrations of AgNPs (C1 = 100 μg/ml, C2 = 50 μg/ml, C3 = 25 μg/ml) by well diffusion method against Gram negative Escherichia coli. The antibacterial performance was assessed by measuring the zone of inhibition (ZOI). Conclusions The results suggested that AgNPs prepared by green approach can be considered as an alternative antibacterial agent.

Eco-friendly biosynthesis and characterization of silver nanoparticles from Solanum lycopersicum (Tomato) peel waste and its application in disinfecting metallic surfaces

“…XRD analysis shows X-ray diffraction (XRD) patterns of TPE-AgNPs detected two peaks of biosynthesized TPE-AgNPs from tomato peels extract at 1.54060mm, the peaks were observed in a range between (0-70 ) and they were located at 4.5 and 18.0 which is in a range below 20 . In another study using the bio-reduction method, the XRD result was four peaks ranging between 10-25nm, they were pure crystalline and had an average size of 7.0nm 22 which is approximately similar compared to the current results. Functional groups of carboxyl, hydroxyl, and phenolic groups existed by the FTIR spectrum.…”

Phytosynthesis of silver nanoparticles using aqueous sandalwood (Santalum album L.) leaf extract: Divergent effects of SW-AgNPs on proliferating plant and cancer cells

“…A few unassigned peaks observed ( Fig 5A and 5B ) could be due to the presence of bioorganic compounds/protein(s) from the leaf extract that crystallizes on the surface of the silver or due to AgNO 3 , which might not have been reduced and hence remain in the sample in trace quantity. Such additional XRD peaks have been observed in other reports of phytosynthesized silver nanoparticles [ 52 , 55 , 56 ]. The observed noise in the XRD could be due to very tiny nanoparticles in the synthesized samples, and also from macromolecules derived from plant extract that are responsible for reduction and capping of silver nanoparticles as suggested by Amargeetha and Velavan, 2018 [ 57 ].…”

In silico Prediction of Malvaviscus arboreus Metabolites and Green Synthesis of Silver Nanoparticles – Opportunities for Safer Anti-Bacterial and Anti-Cancer Precision Medicine

“… 49 The specificities and function are dictated by the biochemical properties of the structure and their functional groups. Standard AgNPs are known to have cytotoxic properties in vitro, 50 but with green synthesis, therapeutic secondary plant metabolites surrounding the silver nucleus can lead to additional properties 51 and possibly a targeted approach that leads to selectivity towards certain types of diseased cells, broadening the safety index and the therapeutic implications of the treatment possibly contributing to precision medicine. Thus, it is reasonable to assume that it is the functional groups present in the secondary metabolites surrounding the NPs that dictate the cytotoxic activity, selectivity, and safety profile.…”