Green Synthesis, Characterization and Applications of Silver Nanoparticles using Thunbergia grandiflora Roxb.

Green synthesis of silver nanoparticles from the leaf extract of Thunbergia grandiflora Roxb. was carried out by bioreduction of silver nitrate to silver nanoparticles due to the presence of biological compounds present in the leaf. The reaction mixture showed a colour change from colourless to reddish brown. The characterization of silver nanoparticles was done by using UV-Visible spectroscopy, FTIR, and TEM. For UV-Visible spectrometry the strong surface plasmon resonance centered at 436 nm. The FTIR analysis showed prominent bands of absorbance at 598.35, 1634.05, 2079.30, 2333.3 and 3332.60 cm-1. TEM analysis revealed that most of the particles fall in the size range from 0 – 5 nm with an average size of 2.39 nm and the particles were spherical in shape. The nanoparticles obtained were checked for its antibacterial activity by disc diffusion method. The silver nanoparticles showed positive results with Klebsiella planticola, but didn’t show any antibacterial effect against Bacillus subtilis. The silver nanoparticles also positively influenced on seed germination and growth by escalating the germination percentage and growth rate of seedlings.