Green synthesis and characterization of gold nanoparticles using the marine macroalgae Sargassum muticum

Green biological synthesis of metallic nanoparticles is an important method in improved techniques of eco-friendly nanoparticle production. In the present study, gold nanoparticles (Au-NPs) were synthesized using of the brown marine algae Sargassum muticum (S. muticum) aqueous extract as both a reductant and a capping agent. The treatment of aqueous solution of gold precursors with S. muticum algae extract resulted in rapid formation of stable nanoparticles for gold. The growth of nanoparticles is monitored by UV-Vis spectrophotometer and complemented with characterization using transmission electron microscopy (TEM), X-ray diffraction, and zeta potential. The formation of Au-NPs was confirmed through the presence of an absorption peak at 550 nm using a UV-Vis spectrophotometer. A TEM image showed that the particles are spherical in shape with a mean size of 5.42 +/- A 1.18 nm. The capping of anionic bio-compounds on the surface of nanoparticles was confirmed by zeta potential measurement (-35.8 mV) and is responsible for the electrostatic stability. The bio-synthesized Au-NPs are expected to have notable applications in pharmaceutical and biomedical applications.