Algal Extract Mediated Silver Nanoparticles Characterization and Antibacterial Activity

Abstract

Silver nanopartilces was synthesized by green chemistry biogenic method using Dyctyota dichotoma aqueous extract under the bright sunlight in 20 min at pH 7.5. Dyctyota dichotoma aqueous extract acts as a capping agent in nanoparticle synthesis. The synthesized Dd-AgNPs were characterized by UV-vis spectroscopy, HR-TEM, DLS, zeta potential and FT-IR. The SPR peak of Dd-AgNPs was produced at 422nm. The Dd-AgNPs was found to be spherical shape with average size of 24nm. The synthesized Dd-AgNPs was highly stabled. The antibacterial activity of different concentration of Dd-AgNPs against both Gram positive and Gram negative bacteria were analyzed by the agar well diffusion assay method. Dd-AgNPs inhibited the growth of bacteria in the concentration manner. The maximum zone of inhibition12mm, 19mm, 17mm and 18mm were obtained at 100μg/ml concentration for Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa respectively. While comparing with control antibiotic, the synthesized Dd-AgNPs has excellent antibacterial activity against Gram positive pathogenic bacteria such as Enterococcus faecalis, Staphylococcus aureus.