Optimization of effective parameters on the suspension durability of green synthesis silver nanoparticles and evaluation their antimicrobial effect

Background & Aim: There have been many studies on green synthesis so far, but the parameters affecting the stability of the nanoparticle suspension have been ignored. The stability of nanoparticles over time is one of the key features for their application. Methods: This experimental study was carried out in 2019. The effect of plant extract concentration, silver nitrate concentration, and time of sun exposure on the synthesis and stability of the nanoparticle suspension was studied. The antibacterial effects of nanoparticles were evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative bacteria (Escherichia Coli). Results: The rapid and biocompatible green synthesis of silver nanoparticles was performed using plant extract. Increasing the extract volume from 3 to 30 ml resulted in a 3-month decrease in nanoparticle stability. Conclusion: In the synthesis of nanoparticles, the best conditions for synthesis of stable silver nanoparticles were when using an extract volume of 3 ml, 1 mM silver nitrate concentration and 10 min reaction time under sunlight. The sunlight was a key factor in the synthesis of nanoparticles. These nanoparticles have good antibacterial activity against all test bacteria.