Abstract

In this study, biosynthesis of silver nanoparticles (AgNPs) using cell-free extract of Santalum album tender leaf
was undertaken, and antioxidant capacity of the synthesized nanoparticles was evaluated. Ultraviolet-visible
spectrophotometer analysis confirmed the production of AgNPs at 430-460 nm where the color change in the solution
from light yellow to brown indicated the formation of AgNPs. The scanning electron microscope studies revealed
the presence of nanoparticles of size ranging from 80 to 90 nm and energy dispersive X-ray confirmed the elemental
composition. Fourier transform infrared analysis confirmed the capping of nanoparticles with organic residues
such as, proteins, amino acids, and polyphenols present in the extract, which led to stabilization of nanoparticles.
Plant extracts are known to contain polyphenols, flavonoids, tannins, which are known to be antioxidants. Therefore,
an attempt was made to see if the biosynthesized AgNPs had better antioxidant activity compared to the extract
by checking its antioxidant activities such as total phenolic content, total flavonoid content assay, 2,2-diphenyl-1-
picrylhydrazyl free radical scavenging assay, and total antioxidant capacity. Biocapped nanoparticles were found to
retain its antioxidant capacity, but free radical scavenging ability was less than the extract.