Sohrabnezhad Sh, Rassa M, Mohammadi Dahanesari E
Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht, Iran.
Department of Biology, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht, Iran.
J Photochem Photobiol B. 2016 Oct;163:150-5. doi: 10.1016/j.jphotobiol.2016.08.018. Epub 2016 Aug 13.
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.
在本研究中，通过分散法在黑暗条件下制备了蒙脱石（MMT）中的卤化银（AgX，X = Cl、Br、I）。硝酸银用作银前驱体。通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、透射电子显微镜（TEM）和紫外-可见漫反射光谱（DRS）对纳米复合材料（NCs）（AgX-MMT）进行了表征。粉末X射线衍射表明氯化银和溴化银纳米颗粒（NPs）插层进入了粘土的层间空间。漫反射光谱表明，对于AgCl-MMT和AgBr-MMT纳米复合材料，在可见光区域有一个宽的表面等离子体共振（SPR）吸收带，这是由金属银纳米颗粒（Ag NPs）产生的。但对于AgI-MMT纳米复合材料，结果则相反。通过平板扩散法研究了纳米复合材料对革兰氏阳性菌，即金黄色葡萄球菌和藤黄微球菌，以及革兰氏阴性菌，即大肠杆菌、铜绿假单胞菌的抗菌活性。对金黄色葡萄球菌、藤黄微球菌和大肠杆菌的抗菌效果顺序为：AgCl-MMT>AgBr-MMT>AgI-MMT。未检测到对铜绿假单胞菌的抗菌活性。
