Biomedical Engineering Graduate Program, The University of Western Ontario, London, ON, Canada.
Nanotechnology. 2011 Mar 18;22(11):115603. doi: 10.1088/0957-4484/22/11/115603.
TiO2 photocatalysts have been found to kill cancer cells, bacteria and viruses under mild UV illumination, which offers numerous potential applications. On the other hand, Ag has long been proved as a good antibacterial material as well. The advantage of Ag-TiO2 nanocomposite is to expand the nanomaterial's antibacterial function to a broader range of working conditions. In this study neat TiO2 and Ag-TiO2 composite nanofilms were successfully prepared on silicon wafer via the sol-gel method by the spin-coating technique. The as-prepared composite Ag-TiO2 and TiO2 films with different silver content were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) to determine the topologies, microstructures and chemical compositions, respectively. It was found that the silver nanoparticles were uniformly distributed and strongly attached to the mesoporous TiO2 matrix. The morphology of the composite film could be controlled by simply tuning the molar ratio of the silver nitrate aqueous solution. XPS results confirmed that the Ag was in the Ag(0) state. The antimicrobial effect of the synthesized nanofilms was carried out against gram-negative bacteria (Escherichia coli ATCC 29425) by using an 8 W UV lamp with a constant relative intensity of 0.6 mW cm(-2) and in the dark respectively. The synthesized Ag-TiO2 thin films showed enhanced bactericidal activities compared to the neat TiO2 nanofilm both in the dark and under UV illumination.
TiO2 光催化剂在弱紫外光照射下已被发现能杀死癌细胞、细菌和病毒，这为其提供了许多潜在的应用。另一方面，Ag 长期以来一直被证明是一种良好的抗菌材料。Ag-TiO2 纳米复合材料的优势在于将纳米材料的抗菌功能扩展到更广泛的工作条件。本研究采用溶胶-凝胶法，通过旋涂技术在硅片上成功制备了纯 TiO2 和 Ag-TiO2 复合纳米薄膜。通过扫描电子显微镜（SEM）、原子力显微镜（AFM）、X 射线衍射（XRD）和 X 射线光电子能谱（XPS）分别对所制备的不同银含量的复合 Ag-TiO2 和 TiO2 薄膜进行了表征，以确定其拓扑结构、微观结构和化学成分。结果发现，银纳米颗粒均匀分布并牢固地附着在介孔 TiO2 基体上。通过简单地调整硝酸银水溶液的摩尔比，可以控制复合膜的形态。XPS 结果证实 Ag 处于 Ag(0)态。通过使用恒定相对强度为 0.6 mW cm(-2)的 8 W 紫外灯和在黑暗中分别对革兰氏阴性菌（Escherichia coli ATCC 29425）进行合成纳米薄膜的抗菌效果测试。与纯 TiO2 纳米薄膜相比，合成的 Ag-TiO2 薄膜在黑暗中和紫外光照射下都表现出增强的杀菌活性。
