School of Biological Sciences, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland.
Int J Antimicrob Agents. 2010 Sep;36(3):280-3. doi: 10.1016/j.ijantimicag.2010.05.006. Epub 2010 Jun 26.
Silver nanoparticles (AgNPs) were synthesised by reducing silver salts using NaBH(4) followed by capping with varying concentrations of beta-cyclodextrin (beta-CD) and were physically characterised. Antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was determined by a microtitre well method. The AgNPs were spherical under transmission electron microscopy, whilst dynamic light scattering showed average diameters of capped particles to be smaller (4-7 nm) than their uncapped equivalents (17 nm). Capped particles demonstrated superior photostability when exposed to intense ultraviolet radiation for 4h as well as significantly (P<0.05) higher (up to 3.5-fold) antibacterial activity. The influence of beta-CD concentration was seen to delay bacterial growth, indicating that a Trojan horse mechanism may be occurring owing to bacterial carbohydrate affinity, thereby enhancing silver ion absorption.
银纳米粒子（AgNPs）通过使用 NaBH（4）还原银盐来合成，然后用不同浓度的β-环糊精（β-CD）进行封端，并进行物理特性分析。通过微量滴定法测定了对大肠杆菌、铜绿假单胞菌和金黄色葡萄球菌的抗菌活性。透射电子显微镜下观察到 AgNPs 呈球形，而动态光散射显示封端颗粒的平均直径较小（4-7nm），小于未封端的颗粒（17nm）。在暴露于强烈的紫外辐射 4 小时后，封端颗粒表现出更好的光稳定性，并且抗菌活性显著提高（P<0.05），最高可达 3.5 倍。β-CD 浓度的影响可延迟细菌生长，表明可能由于细菌碳水化合物亲和力而发生特洛伊木马机制，从而增强银离子吸收。
