Macromolecular arabinogalactan polysaccharide mediated synthesis of silver nanoparticles, characterization and evaluation

Extremely stable and spherical silver nanoparticles (AgNPs) were synthesized using a simple and ecofriendly approach by using the arabinogalactan mucilage of portulaca, a food grade natural polysaccharide complex. The aqueous solution of mucilage served as both reducing agent and stabilizer in this reaction. The resulting nanoparticles were spherical with a diameter of 20-30 nm. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR), atomic absorption spectroscopy (AAS), dynamic light scattering (DLS) and UV-visible spectroscopy (UV-Vis) techniques were used to characterize and study the reaction mechanism of generated silver nanoparticles. A reaction mechanism was devised for the formation of arabinogalactan stabilized silver nanoparticles. The reaction of resulting AgNPs against bacterial and fungal strains has shown that they are more potent against gram-negative bacterial strains. The reduction reaction of 4-nitrophenol catalyzed by arabinogalactan-stabilized AgNPs showed good catalytic activity towards the formation of 4-amino phenol within 10 min of time.