Abstract
Background and Objective: Silver nanoparticles were synthesized via chemical reduction and using stabilizers agents. This study aimed to compare between biosynthesis of silver nanoparticles (AgNPs) by marine alga Ulva fasciata (U. fasciata) as reducing and stabilizing agents with biosynthesis of AgNPs by marine alga U fasciata as reducing agents and sodium dodecyl sulfate as stabilizer against bacterial activities. Materials and Methods: In this study macro green alga (Ulva fasciata) aqueous extracts using as reducing agents to reduce Ag ions to Ag and sodium dodecyl sulfate (SDS) as stabilizer. Ultra violet-visible spectroscopy, transmission electron microscope (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy (EDX). Zeta potential and zeta sizer were used to characterize green synthesis silver nanoparticles (AgNPs). Results: Biosynthesis of AgNPs showed broad surface plasmon resonance peak at 446, 428 and 426 nm with 1 h and 1 and 2 weeks that reflects the stability of nanoparticles until 2 weeks. Transmission electron microscopy study proved that the shape is spherical and average size was ranged from 9-20 nm. Fourier transform infrared spectroscopy analysis (FTIR) indicated evidence that pretence of amide band of protein as possible reducing agents. Zeta potential was at-30, zeta sizer indicated that the size range around 53.5 nm. Biosynthesis AgNPs had antibacterial activities against Escherichia coli ATTCC 8739, Proteus mirabilis ATTCC 9240, Micrococcus leutus and Kocuria varians. Conclusion: The biosynthesis of silver nanoparticles using U fasciata aqueous extracts as reducing agents and sodium dodecyl sulfate (SDS) as stabilizer had highest inhibition activity against both Gram-negative and Gram-positive pathogenic bacteria more than silver nanoparticles biosynthesis by U. fasciata aqueous extracts as reducing and stabilizing agents and also AgNO3 as a bulk.