Biosynthesis of Silver Nanoparticles using Echinacea pallida (Nutt.) Nutt. and Antioxidant Activity Thereof

Abstract

In this work, silver nanoparticles (Ep-AgNPs) were synthesised using Echinacea pallida (Nutt.) Nutt. The dried leaves of E. pallida were collected and heated at 55 and#176;C in deionized water, and filtered, and the leaf extract was treated with AgNO3 to produce the Ep-AgNPs. The Ep-AgNPs were analyzed by Ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The characteristic hydroxyl gave the peak at 3147 cm-1. In UV-Vis analysis, observation of absorption band at 468 nm proved the achievement of Ep-AgNPs synthesis. SEM analysis presented the spherical shape of nanostructures with an average size of 77.82 nm. The face-centered crystal structure of Ep-AgNPs was revealed by the XRD analysis. The 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH•) scavenging, ferric reducing antioxidant power (FRAP), 2,2and#39;-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS•+) assays were employed for antioxidant study in which Ep-AgNPs exhibited excellent antioxidant effect. Ep-AgNPs displayed outstanding DPPH• activity (6.34, IC50, and#181;g/ml) compared to the standard BHT (10.78, IC50, and#181;g/ml). The high activity was observed for ABTS•+ and reducing power assays as well. Hence, Ep-AgNPs could be a valuable material for the food and pharmaceutical industry.