Department of Bionano Engineering, Hanyang University, Ansan 426-791, South Korea.
Langmuir. 2011 Aug 16;27(16):10228-33. doi: 10.1021/la201739n. Epub 2011 Jul 12.
The use of silica shells offers many advantages in surface-enhanced Raman scattering (SERS)-based biological sensing applications due to their optical transparency, remarkable stability in environmental media, and improved biocompatibility. Here, we report a novel layer-by-layer method for the preparation of silica-hollow gold nanosphere (HGN) SERS tags. Poly(acrylic acid) was used to stabilize Raman reporter-tagged HGNs prior to the adsorption of a coupling agent, after which a silica shell was deposited onto the particle surface using Stöber's method. Importantly, competitive adsorption of the Raman reporter molecules and coupling agents, which results in unbalanced loading of reporter molecules on individual nanoparticles, was avoided using this method. As a result, the loading density of reporter molecules could be maximized. In addition, HGNs exhibited strong enhancement effects from the individual particles because of their ability to localize the surface electromagnetic fields through pinholes in the hollow particle structures. The proposed layer-by-layer silica-encapsulated HGN tags showed strong SERS signals as well as excellent multiplexing capabilities.
由于其光学透明性、在环境介质中的显著稳定性和改善的生物相容性，硅壳在基于表面增强拉曼散射（SERS）的生物传感应用中具有许多优势。在这里，我们报告了一种用于制备硅空心金纳米球（HGN）SERS 标签的新型层层方法。聚（丙烯酸）用于稳定拉曼报告分子标记的 HGN ，然后在粒子表面使用 Stöber 法沉积硅壳。重要的是，使用这种方法避免了拉曼报告分子和偶联剂的竞争吸附，这会导致报告分子在单个纳米粒子上的负载不平衡。因此，可以最大化报告分子的负载密度。此外，由于 HGN 能够通过空心粒子结构中的小孔来局部化表面电磁场，因此单个粒子表现出很强的增强效果。所提出的层层包裹的硅壳 HGN 标签表现出很强的 SERS 信号和优异的多重检测能力。
