Centre for Research in Nanotechnology and Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Nanoscale. 2013 Aug 21;5(16):7328-40. doi: 10.1039/c3nr00024a.
Antimicrobial materials with immobilized/entrapped silver nanoparticles (AgNPs) are of considerable interest. There is significant debate on the mode of bactericidal action of AgNPs, and both contact killing and/or ion mediated killing have been proposed. In this study, AgNPs were immobilized on an amine-functionalized silica surface and their bactericidal activity was studied concurrently with the silver release profile over time. This was compared with similar studies performed using colloidal AgNPs and AgCl surfaces that released Ag ions. We conclude that contact killing is the predominant bactericidal mechanism and surface immobilized nanoparticles show greater efficacy than colloidal AgNPs, as well as a higher concentration of silver ions in solution. In addition, the AgNP immobilized substrate was used multiple times with good efficacy, indicating this immobilization protocol is effective for retaining AgNPs while maintaining their disinfection potential. The antibacterial surface was found to be extremely stable in aqueous medium and no significant leaching (∼1.15% of total silver deposited) of the AgNPs was observed. Thus, immobilization of AgNPs on a surface may promote reuse, reduce environmental risks associated with leaching of AgNPs and enhance cost effectiveness.
具有固定/包埋银纳米粒子（AgNPs）的抗菌材料引起了相当大的关注。AgNPs 的杀菌作用模式存在很大争议，有人提出接触杀菌和/或离子介导杀菌。在这项研究中，AgNPs 被固定在胺功能化的硅表面上，并随着时间的推移同时研究其杀菌活性和银释放情况。这与使用胶体 AgNPs 和释放 Ag 离子的 AgCl 表面进行的类似研究进行了比较。我们的结论是，接触杀菌是主要的杀菌机制，表面固定的纳米粒子比胶体 AgNPs 更有效，并且溶液中银离子的浓度更高。此外，固定 AgNP 的基底可以多次使用，并且具有良好的功效，表明这种固定化方案在保留 AgNPs 的同时保持其消毒潜力是有效的。在水介质中，抗菌表面非常稳定，AgNPs 的浸出量（约为总沉积银的 1.15%）没有明显变化。因此，将 AgNPs 固定在表面上可能会促进重复使用，降低与 AgNPs 浸出相关的环境风险，并提高成本效益。
