Facile microwave synthesis of silver nanoplates: Optical plasmonic and antimicrobial activity

Nanoparticles of metallic silver (Ag NPs) with nano-plates structure were synthesized in the one-step method by a reduction reaction of silver nitrate solution in a home-made microwave irradiation system. The fabricated samples structure was identified by X-ray diffraction (XRD), UV-vis spectrometer, N₂ physisorption and scanning electron microscope (SEM). X-ray diffraction was exploited to calculate the average crystallite silver nanoparticles size (25.4 nm). UV-vis absorption spectroscopy supports the scattering plasmonic optical properties of colloidal silver nanoparticles. The produced material was investigated as an antimicrobial agent; silver nanoparticles were tested against some Gram-negative bacteria (Pseudomonas aeruginosa, Shigella sp, Proteus sp, Klebsiella pneumonia, Gram-positive bacteria (Staphylococcus aureus) and Candida albicans as a model of fungi. Agar diffusion technique was adopted for an antimicrobial potential investigation of the synthesized material. The fabricated Ag NPs showed higher activity against the pathogenic bacteria. SEM images for the as-got nanopowder exhibit nanoplate's structure. XRD show well-crystalline structure where no crystallites for AgNO₃ was found in the XRD chart. The delivered material has a uniform structure with high surface area (10.1 m² g^-1), which can be utilized as a promising structure for various applications especially in the field of antimicrobials where it has been considered as a highly effective antibiotic against both Gram-positive and Gram-negative bacteria.