Eco‐Friendly Bio‐Fabrication of Silver Nanoparticles by Cenchrus biflorus (Roxb.): Their Characterization and Biological Activity Exploration

Silver nanoparticles (AgNP) have extensive and exceptional applications in a variety of sectors, particularly medicine. We developed an eco‐friendly method to synthesize AgNPs from an extract of Cenchrus biflorus . CB extract was used to make AgNPs using an environmentally friendly process. UV–Vis. spectroscopy was used to obtain an absorbance of 1.9 and a prominent peak at 440 nm. Fourier‐transform infrared spectroscopy revealed some peaks, indicating the presence of distinct phytochemicals that produce AgNPs. AgNPs ~20 nm in diameter and spherical in shape were identified via scanning electron microscopy. The desired bands at 2 θ values of 32.34 o , 38.16 o , and 46.3 o obtained using X‐ray diffraction verified the crystal structure of the AgNPs with a size of 14.59 nm. AgNPs and the plant extract exhibited strong antioxidant activity against 2,2‐diphenyl‐1‐picrylhydrazyl, H 2 O 2 , and ABTS (2,2‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulphonic acid) with maximum Scavenging activities of 82.2% and 75.5%, 72.2% and 65.5%, and 66.2% and 53.5%, respectively. AgNPs and the plant extract also exhibited antimicrobial activity against certain fungal and bacterial strains with a maximum inhibition of 40.2 ± 0.04 and 35.5 ± 0.9 mm against Aspergillus niger , 37.2 ± 0.08 and 31.5 ± 0.9 mm against Aspergillus flavus, 13 ± 0.9 and 10.5 ± 0.5 mm against methicillin‐resistant Staphylococcus aureus , 14.25 ± 0.09 and 11.5 ± 0.9 mm against Streptococcus pyogens , 11 ± 0.9 and 10 ± 0.8 mm against Escherichia coli, and 12 ± 0.9 and 11 ± 0.8 mm against Klebsiella pneumoniae . AgNPs and the plant extract possessed good antidiabetic properties with a maximum inhibition of 65.2% and 53.5%, respectively. Both the plant extract and AgNPs revealed a type of inhibition that competes because their Vmax values remained constant as Km values increased. The anti‐Alzheimer property of AgNPs and the plant extract exhibited a maximum inhibition of 88.6% and 62.2%, and AgNPs and the plant extract confirmed an aspect of noncompetitive inhibition due to which Vmax decreased and Km remained unchanged as the AgNP and plant extract concentrations increased.