Freestanding and Arrayed Nanoporous Microcylinders for Highly Active 3D SERS Substrate
Freestanding and Arrayed Nanoporous Microcylinders for Highly Active 3D SERS Substrate
复制标题
DOI：
10.1021/cm400298e
复制
发表时间：
2013-06-25
影响因子：
8.6
通讯作者：
Yang, Seung-Man
中科院分区：
文献类型：
--
作者：
Lee, Su Yeon;Kim, Shin-Hyun;Yang, Seung-Man
表面增强拉曼散射(SERS)被认为是最有前途的分子分析工具之一。为了开发实用的平台，人们已经制备了各种纳米颗粒和二维(2D)纳米结构。然而，传统方法信号强度低或结合动力学慢限制了它们的应用。为了克服这些缺点，三维(3D)纳米结构的生产和使用仍然是一个重要但尚未得到满足的需求。在本文中，我们报道了一种新型有效的表面增强拉曼散射活性材料，它是通过制备层次化结构的二氧化硅微柱来修饰金纳米颗粒的。为了充分开发3D纳米结构，同时保持分析物分子的快速扩散，我们使用了限制在压印模具微孔中的嵌段共聚物(BCP)的自组装纳米结构；BCP可以通过微相分离提供由直径小于100 nm的纳米纤维组成的3D纳米结构的模板，而印迹技术为BCP的局部限制提供了圆柱形几何形状。然后，通过反应离子刻蚀将具有纳米结构域的微柱转化为具有3D纳米孔的微柱，然后用金纳米颗粒修饰其纳米孔。由此得到的3D纳米孔使金纳米粒子能够高负载，并形成丰富的热点和微柱，促进分析物分子在纳米孔中的快速扩散，导致SERS强度显著增强。
Surface-enhanced Raman scattering (SERS) has been considered as one of the most promising tools for molecular analysis. To develop practical platforms, a variety of nanoparticles and two-dimensional (2D) nanostructures have been prepared. However, low signal intensity or slow binding kinetics in conventional approaches limits their applications. To overcome these shortcomings, production and usage of three-dimensional (3D) nanostructures remain an important yet unmet need. In this paper, we report novel and effective SERS-active materials by fabricating hierarchically structured SiO2 microcylinders decorated with gold nanoparticles. In order to fully develop 3D nanostructures, while maintaining fast diffusion of analyte molecules, we used self-assembled nanostructures of block-copolymers (BCPs) confined in the microholes of an imprinting mold; the BCPs could provide a template for producing 3D nanostructure composed of nanofibers with sub-100 nm diameter through their rnicrophase separation, whereas imprinting technique provided cylindrical geometry for the local confinement of the BCPs. Microcylinders with nanodomains were then transformed into microcylinders with 3D nanopores via reactive-ion etching and, subsequently, their nanopores were decorated by gold nanoparticles. The resultant 3D nanopores enable a high loading of gold nanoparticles and formation of abundant hot spots and microcylinders facilitate the fast diffusion of analyte molecules through the nanopores, resulting in significant enhancement of SERS intensity.