National Creative Research Initiative Center for Integrated Optofluidic Systems, Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 305-701, Korea.
Lab Chip. 2011 Jan 7;11(1):87-92. doi: 10.1039/c0lc00125b. Epub 2010 Oct 20.
In this paper, we demonstrated a microfluidic system for fabricating microspheres with hierarchical surface nanopatterns for molecular detection based on surface-enhanced Raman scattering (SERS). Briefly, a photocurable silica suspension was emulsified into monodisperse droplets using a microfluidic device composed of two coaxial glass capillaries. The silica particles in each droplet protruded through the interface and spontaneously formed a hexagonal array. After polymerization of the droplets, we selectively decorated the exposed areas of the silica particles with silver nanoparticles through electroless deposition. The resulting hierarchically-structured microspheres showed high sensitivity and fast binding kinetics in molecular detection based on SERS, owing to the dense array of hot spots on each microsphere and high mobility of the microspheres, respectively. Notably, the SERS signals from molecules adsorbed on the microspheres could be detected in both the dried and suspension states. In addition, we demonstrated that the SERS-active microspheres can be functionalized into structural colored or magnetoresponsive microspheres for advanced applications.
本文展示了一种基于表面增强拉曼散射（SERS）的用于制造具有分级表面纳米图案的用于分子检测的微球的微流控系统。简要地说，光固化的二氧化硅悬浮液使用由两个同轴玻璃毛细管组成的微流控装置乳化成为单分散液滴。每个液滴中的二氧化硅颗粒通过界面突出并自发形成六方排列。在液滴聚合之后，我们通过无电沉积选择性地用银纳米颗粒修饰暴露的二氧化硅颗粒的区域。由于每个微球上的热点密集排列以及微球的高迁移率，所得的分级结构微球在基于 SERS 的分子检测中表现出高灵敏度和快速结合动力学。值得注意的是，在干燥和悬浮状态下都可以检测到吸附在微球上的分子的 SERS 信号。此外，我们证明了 SERS 活性微球可以官能化为结构色或磁响应性微球，用于高级应用。
