Biosynthesis of Silver Nanoparticles from halophilic Green Algae (<i>Dunaliella viridis</i>) Extract and it is Antibacterial activity

Biological synthesis of nanoparticles is a new area of nanotechnology that has advantages in terms of cost and the environment compared to chemical or physical synthesis methods. The current work is carried out to synthesize silver nanoparticles (AgNPs) utilizing green algae (Dunaliella viridis Teodoresco 1905) extract as a reducing and capping agent and to evaluate the antibacterial efficacy of AgNPs. The. The measures of UV-V spectroscopy, XRD, TEM, SEM-EDSand FTIR were used to characterize the synthesized silver nanoparticles. Additionally, agar well diffusion and minimum inhibitory concentration (MIC) methods were used for antibacterial activity. The plasmon absorbance of AgNPs was associated with a peak at 475 nm observed in the UV spectrum of the aqueous medium containing silver particles. The XRD spectrum of AgNPs revealed certain distinctive peaks, indicating a face-centered cubic lattice and crystalline structure with 36.73 nm in size. According to TEM and SEM images, the fabricated AgNPs were spherical, and EDX agreed to the presence of AgNPs by displaying a strong banner in the silver region. Moreover, functional interactions between secondary algal metabolites and AgNPs were confirmed by the FTIR spectrum. The bioactivity of nanoparticles showed a substantial antibacterial effect against gram-negative bacteria Escherichia coli and gram-positive bacteria Staphylococcus aureus.