Biosynthesis and Characterization of Silver Nanoparticles Using Sodium Alginate from the Invasive Macroalga Sargassum muticum

Silver nanoparticles (AgNPs) were synthesized using sodium alginate extracted from the invasive macroalga Sargassum muticum harvested from the Atlantic coast of Morocco. The characterization of silver nanoparticles was determined by various analytical techniques (UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA)). The X-ray diffraction patterns proved the crystal phase of AgNPs. The interaction of the functional groups of sodium alginate in the AgNPs was confirmed by FTIR analysis. They were spherical in shape with average size around 21.95 ± 0.96 nm and they exhibit important thermal stability. The in vitro antimicrobial activity of the synthesized nanoparticles exhibited high antibacterial activity against the tested human pathogenic bacteria Bacillus cereus, Micrococcus luteus, Staphylococcus aureus, and Pseudomonas aeruginosa. These eco-friendliness alginate-mediated silver nanoparticles may serve as antibacterial agents for pharmaceutical applications.