Department of Chemistry , University of Calgary , Calgary , Alberta , Canada T2N 1N4.
Institut Quimic de Sarria , Universitat Ramon Llull , Barcelona 08029 , Spain.
J Am Chem Soc. 2019 Jan 9;141(1):684-692. doi: 10.1021/jacs.8b12206. Epub 2018 Dec 20.
Plasmonic nanoparticles can strongly interact with adjacent photosensitizer molecules, resulting in a significant alteration of their singlet oxygen (O) production. In this work, we report the next generation of metal-enhanced O nanoplatforms exploiting the lightning rod effect, or plasmon hot spots, in anisotropic (nonspherical) metal nanoparticles. We describe the synthesis of Rose Bengal-decorated silica-coated silver nanocubes (Ag@SiO-RB NCs) with silica shell thicknesses ranging from 5 to 50 nm based on an optimized protocol yielding highly homogeneous Ag NCs. Steady-state and time-resolved O measurements demonstrate not only the silica shell thickness dependence on the metal-enhanced O production phenomenon but also the superiority of this next generation of nanoplatforms. A maximum enhancement of O of approximately 12-fold is observed with a 10 nm silica shell, which is among the largest O production metal enhancement factors ever reported for a colloidal suspension of nanoparticles. Finally, the Ag@SiO-RB NCs were benchmarked against the Ag@SiO-RB nanospheres previously reported by our group, and the superior O production of Ag@SiO-RB NCs resulted in improved antimicrobial activities in photodynamic inactivation experiments using both Gram-positive and -negative bacteria model strains.
等离子体纳米粒子可以与相邻的光敏剂分子强烈相互作用，导致其单线态氧（O）产生的显著改变。在这项工作中，我们报告了下一代利用避雷针效应或等离子体热点的金属增强 O 纳米平台，该效应存在于各向异性（非球形）金属纳米粒子中。我们描述了基于优化方案合成的玫瑰红修饰的二氧化硅包覆银纳米立方体（Ag@SiO-RB NCs），该方案可以得到高度均匀的 Ag NCs，其二氧化硅壳厚度范围为 5 至 50nm。稳态和时间分辨的 O 测量不仅证明了二氧化硅壳厚度对金属增强 O 产生现象的依赖性，而且还证明了这种下一代纳米平台的优越性。用 10nm 的二氧化硅壳观察到 O 的最大增强约为 12 倍，这是在胶体悬浮液中纳米粒子的金属增强因子中最大的 O 产生之一。最后，将 Ag@SiO-RB NCs 与我们之前报道的 Ag@SiO-RB 纳米球进行了基准测试，Ag@SiO-RB NCs 优越的 O 产生导致在使用革兰氏阳性和阴性细菌模型菌株的光动力失活实验中改善了抗菌活性。
