Biosynthesis of Silver Nanoparticles from Polyphenolic Extract of Baliospermun solanifolium using Central Composite Design

Background: Plant extracts contain a considerable amount of polyphenols. These polyphenols act as reducing, capping, and stabilizing agents in the formation of silver nanoparticles. Objectives: The objective of the current study is biosynthesis, optimization, and evaluation of silver nanoparticles from the polyphenolic extract of Baliospermum solanifolium. Materials and Methods: Central composite design (CCD) was used to synthesize silver nanoparticles (AgNPs) from the polyphenolic extract of Baliospermum. Preliminary screening was done to find out the upper and lower limits for the optimization study. Four independent variables like Silver nitrate concentrations (mM), Baliospermum extract (%), stirring time (min), and stirring rate (RPM) were employed. As per the design expert, 30 experiments were performed and their effects on dependent variables were listed. Analysis of synthesized AgNPs was done by visual observation, UV-vis Spectroscopy, Zeta potential, X-ray Diffraction (XRD), FTIR, FESEM, etc. Results: The development of Baliospermum silver nanoparticles was confirmed by a color change from pale yellow to dark brown. Characteristic peak of silver nanoparticles observed at 432 nm. −15 mV Zeta potentials confirmed the stability of silver nanoparticles. The sizes of the produced nanoparticles were measured using a FESEM and ranged from 70 to 140 nm. The crystalline nature of nanoparticles was confirmed with the help of X-ray crystallography. FTIR data strongly revealed the presence of phenolic compounds in the reduction, stabilization, and biosynthesis of AgNPs. Conclusion: Major Optimized factors offered by the Central composite design were 10mM AgNO3, 10 % Baliospermum extract, 150 min, and 700 rpm. As per the data collected from FTIR and HPLC, silver nanoparticles could be capped with major phenolic groups like ellagic acid, catechins, and quercetin.