One-step synthesis and characterization of anisotropic silver nanoparticles: application for enhanced antibacterial activity of natural fabric

A simple one-step chemical reduction method was employed for the synthesis of truncated triangular silver nanoparticles (Ag-NPs). The reduction of Ag ions by sodium borohydride was performed in the presence of poly(vinyl pyrrolidone) as a stabilizing agent. The synthesized Ag-NPs were characterized by UV–Vis spectroscopy, transmission electron microscopy, dynamic light scattering, FT-Raman spectrometer and X-ray diffraction in order to study optical, morphological, compositional, and structural properties. The UV–Vis spectrum showed three plasmon peaks located at 340, 412, and 700 nm, confirmed the anisotropic Ag-NPs. The average edge length of 22 ± 5 nm was observed from TEM images for truncated triangular Ag-NPs. From XRD pattern it was confirmed that the Ag-NPs were polycrystalline in nature, with preferential orientation along (111) lattice plane. The antibacterial susceptibility of Ag-NPs-treated fabrics were tested by Kirby–Bauer disk-diffusion test and American Association of Textile Chemists and Colorists (AATCC) test method 100-2004 against Gram-positive and Gram-negative bacteria. The Ag-NPs treated fabrics showed more pronounced antibacterial activity against Gram-negative bacteria than that of Gram-positive bacteria.