Green synthesis of silver nanoparticles using fresh water green alga Pithophora oedogonia (Mont.) Wittrock and evaluation of their antibacterial activity

In the present study, we report the aqueous extract of Pithophora oedogonia to produce silver nanoparticles (AgNPs) by reduction of silver nitrate. It was noted that synthesis process was considerably rapid and silver nanoparticles were generated within few minutes of silver ions coming in contact with the algal extract. A peak at 445 nm corresponding to the plasmon absorbance of AgNPs was noted in the UV–vis spectrum of the aqueous medium that contained silver ions. Scanning electron microscopic (SEM) and dynamic light scattering analysis of colloidal AgNPs indicated the size of 34.03 nm. Energy-dispersive X-ray spectroscopy revealed strong signals in the silver region and confirmed of the AgNPs. Fourier transform infrared spectroscopic analysis of the nanoparticles indicated the presence of protein which was regarding a capping agent surrounding the AgNPs. Moreover, the antibacterial activity of synthesized nanoparticles exhibited potential inhibitory activity against seven tested pathogenic bacteria.