Antioxidant, antidiabetic, and anti‐Alzheimer performance of green synthesized silver, gold, and silver/gold bimetallic nanoparticles

Abstract

Nanotechnology can be used to produce nanoparticles (NPs) through the green route by using plant extract. NPs can be synthesized in many ways, but there is a growing need to build up high‐yield, low‐priced, harmless, and eco‐friendly procedures; thus, the green synthesis of NPs is one recent advancement in nanotechnology and nanoscience. The current study is designed for the development of an easy, feasible, and eco‐friendly, method for the biosynthesis of silver/gold (Ag/Au) monometallic NPs (MNPs) and their Ag/Au bimetallic NPs (BNPs) by using the metabolic extract of the novelHippeastrum hybridum(HH) plant. The HH plant has not previously been used in the synthesis of BNPs. These NPs were then tested for their potential as a scavenger of different free radicals, that is, ferric chloride, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), hydrogen peroxide (H2O2), 2,2 azobis, 3‐ethyl benzothiazoline‐6‐sulphonic acid (ABTS), ammonium molybdate, anti‐enzyme activity against alpha‐amylase (α‐amylase), and snake venom enzyme acetylcholinesterase (AChE) to check their potential as antioxidants by using ultraviolet–visible (UV–vis) spectroscopy, energy dispersive x‐ray (EDX), scanning electron microscopy (SEM), x‐ray diffraction (XRD), and Fourier transform infrared (FT‐IR) spectroscopy investigations, MNPs and BNPs were both identified. According to UV–vis sharp peaks at 417, 576, and 542 nm were recorded, which corresponded to AgNPs, AuNPs, and BNPs, respectively. According to XRD examination, the crystal structure contains Ag, Au, and Ag/Au BNPs with average sizes of 13.3, 10.72, and 8.34 nm, respectively. Ag, Au, and Ag/Au BNPs possessed morphologies that were asymmetrical, according to SEM, and were calculated to be 40, 30, and 20 nm in size, respectively. The signal of Ag of the HH‐AgNPs was confirmed to be 22.75%, the Au signal of the HH‐AuNPs to be 48.08%, the Ag signal to be 12%, and the elemental Au signal to be 38.26% of the Ag/Au BNPs. The BNPs showed more significant activities as free radical scavengers with 86.58 ± 0.031 (ferric chloride), 50 ± 0.052 (molybdenum), 69.1 ± 0.31 (DPPH), 64.15 ± 0.31 (H2O2), and 70.55 ± 0.08 (ABTS) 50% inhibitory concentrations. BNPs competitively inhibit α‐amylase (Vmaxremained unchanged,Kmincreased from 10.65% to 84.37% and 10.75% to 132.76%, respectively), while in the case of AChE,Kmremained constant andVmaxdecreased from 23.62% to 40.26% due to a non‐competitive type of inhibition. However, further research is suggested to reduce the drawbacks of NPs.