Green Synthesis of Silver Nanoparticles from Root Extracts of <i>Rubus ellipticus</i> Sm. and Comparison of Antioxidant and Antibacterial Activity

Abstract

The fabrication of metal nanoparticles through green synthetic pathways using plant extracts has increased attention due to low cost, benevolent methods, fewer hazardous byproducts, and applications. Silver nanoparticles (AgNPs) were synthesized by reacting to aqueous root extracts of Rubus ellipticus Sm. (RERE) with AgNO 3 solution (1 mM) at an ambient condition. The visual change of color from light yellow to reddish brown and the absorption peak at 416‐420 nm in the UV‐visible spectra indicated the formation of AgNPs in the solution. The shifting of the positions in the FTIR spectra indicated the potential role of the functional groups as capping and stabilizing agents. The powder XRD diffractogram exposed the crystalline nature of the nanoparticles. The surface morphology and the elemental composition of the AgNPs were established by the FESEM and EDX analysis. The TEM images revealed the spherical and monodispersed nanoparticles of size ranging from 13.85 to 34.30 nm with an average of 25.20 ± 7.01 nm ( n = 10). The biogenic AgNPs showed a better 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity with lower IC 50 (13.83 ± 0.33 μ g/mL) as compared to that of the RERE with IC 50 (15.86 ± 4.14 μ g/mL). The synthesized AgNPs showed higher zones of inhibition (ZOI) on the agar well diffusion method against Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), and Klebsiella pneumoniae (ATCC 700603). The result of this study highlights the potential benefits of R. ellipticus root extract‐based AgNPs for biomedical practices.