The Biosynthesis of Silver Nanoparticles Using the Extract of the Algae Cladophora crispata and Testing their Antibacterial Activity.

The present research aimed to investigate the potential of the ethanolic extract of Cladophora crispata algae for synthesizing AgNPs. The GC-mass technique was used in the identification of active compounds present in the algal ethanolic extract. The extract’s capability to synthesize silver nanoparticles was examined, as well as the formation of these nanoparticles was deduced by the color transformation of the mixture from light green to dark brown. Some of the techniques used to characterize the synthesized nanoparticles include an Ultraviolet-Visible spectrophotometer (UV-vis), Fourier Transform Infrared (FTIR) spectroscopy, a Scanning Electron Microscope (SEM), and Energy-Dispersive X-ray spectroscopy (EDX). They were also characterized by X-ray Diffraction (XRD). The antibacterial effectiveness was tested through the Agar well diffusion method. The GC-mass results indicated that the ethanolic extract of the algae contains different active compounds with different percentages of each,such as Oleic acid (11.7%), Neophytadiene (12.0%), and n-Hexadecanoic acid (283.1%). UV-vis absorption spectroscopy was used to confirm the formation of the silver nanoparticles, which appeared at a wavelength of 417nm. The XRD analysis confirmed the crystalline nature of the resulting silver nanoparticles, while SEM revealed that the AgNPs were spherical with particle sizes between 29-99 nm. EDX analysis revealed that the synthesized silver nanoparticles were composed of silver, carbon, oxygen, and chlorine. The efficacy of the synthesized silver nanoparticles was tested against four types of pathogenic bacteria, namely E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. The results demonstrated that the silver nanoparticles had a significant inhibitory capability against these pathogens.