title: Spectroscopic study of silver halides in montmorillonite and their antibacterial activity.
abstract: In this study silver halides (AgX, X=Cl, Br, I) in montmorillonite (MMT) were prepared by dispersion method in dark. AgNO3 was used as a silver precursor. The nanocomposites (NCs) (AgX-MMT) were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The powder X-ray diffraction showed intercalation of AgCl and AgBr nanoparticles (NPs) into the clay interlayer space. The diffuse reflectance spectra indicated a broad surface plasmon resonance (SPR) absorption band in the visible region for AgCl-MMT and AgBr-MMT NCs, resulting of metallic Ag nanoparticles (Ag NPs). But the results were opposite in case of AgI-MMT NC. The antibacterial activity of NCs was investigated against Gram-positive bacteria, i.e., Staphylococcus aureus and Micrococcus luteus and Gram-negative bacteria, i.e., Escherichia coli, Pseudomonas aeruginosa, by the well diffusion method. The antibacterial effects on Staphylococcus aureus, Micrococcus luteus and Escherichia coli decrease in the order: AgCl-MMT>AgBr-MMT>AgI-MMT. No antibacterial activity was detected for Pseudomonas aeruginosa.
authors: Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht, Iran. Electronic address: sohrabnezhad@guilan.ac.ir.
authors: Sh
authors: Sh
authors: Sohrabnezhad
authors: Department of Biology, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht, Iran.
authors: M
authors: M
authors: Rassa
authors: Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht, Iran.
authors: E
authors: E
authors: Mohammadi Dahanesari
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001546:Bentonite / Q000737:chemistry*; D006219:Halogens / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010316:Particle Size; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology*; D013057:Spectrum Analysis
chemical_list: D000900:Anti-Bacterial Agents; D006219:Halogens; D001546:Bentonite; D012834:Silver
keywords: Silver halides loaded montmorillonite; Surface morphology; Surface plasmon resonance; X-ray diffraction, antibacterial activity