LAUSR

A cost-effective, and rapid method to synthesize gold nanoparticles using Chenopodium aristatum L. stem extract was developed in this study. Chenopodium aristatum L. is an obnoxious weed. Their tenacious vitality can provide us enormous biomass for beneficial utilizations. In this paper, its stem extract was used as both capping and reducing agents for the biosynthesis of gold nanoparticles (AuNPs). UV–Vis spectra showed surface plasmon resonance (SPR) band at ~540 nm. The synthesized AuNPs were quantified by the centrifugal ultrafilter method followed with ICP-MS determination. TEM images showed that the shapes of synthesized AuNPs were predominantly spherical. In addition, truncated triangular and small amounts of other shaped NPs were also formed. The results of SAED showed clear circular spots. The face-centered cubic structure of the AuNPs was confirmed by XRD peaks at 38.188°, 44.552°, 64.589°, and 77.584°, which corresponded to (111), (200), (220), and (311) planes, respectively. Zeta (ζ) potential of AuNPs was −22.9 ± 5.56 mV. FTIR spectrum showed the functional groups, such like O–H, N–H, C–H, C=O, were possibly responsible for reducing Au(III) ions and stabilizing nanoparticles. The synthesized AuNPs exhibited good catalytic and antioxidant activities in degradation of 4-nitrophenol and free radical scavenging.