Chlorella minutissima -assisted silver nanoparticles synthesis and evaluation of its antibacterial activity.

The conventional methods of nanoparticles synthesis led to the production of highly toxic by-products and the use of toxic chemicals that are highly expensive in nature. Thus, the recent past has witnessed a surge in green synthesis of nanoparticles as a sustainable alternative. The present study outlines the biogenic silver nanoparticles (Ag-NPs) synthesis from an aqueous extract of Chlorella minutissima . The effect of certain parameters such as the reaction mixture's pH and precursor metal solution to algal extract ratios were explored and optimized. The UV spectrophotometric analysis of Ag-NPs gave surface plasmon response maximally at 426 nm. The developed Ag-NPs were characterized using zeta potential, indicating their high stability (-21.2 mV) with a mean diameter of 73.13 nm. Results from field emission-scanning electron microscopy (FE-SEM) showed that the particles were spherical in shape. Ag-NPs synthesized using Chlorella minutissima extract could significantly inhibit the growth of both Gram-positive and Gram-negative bacterial species. The study highlights that using C. minutissima extract for Ag-NPs synthesis is a convenient and fast process for controlling the growth of Gram-positive as well as Gram-negative bacteria.