Department of Chemistry and KI for the NanoCentury, KAIST, Daejeon 305-701, Korea.
ACS Appl Mater Interfaces. 2012 Sep 26;4(9):5038-43. doi: 10.1021/am3015058. Epub 2012 Aug 20.
Plasmonic nanostructures with tunable optical properties and their designed spatial arrangements can facilitate a variety of application ranging from plasmonics to biosensors with unprecedented sensitivity. Here we describe a facile and versatile method for fabricating tunable plasmonic substrates based on the reshaping of metal nanocrystals. Anisotropic etching and redeposition of Ag atoms mediated by halide ions transformed Ag nanoprisms deposited on two- or three-dimensional surfaces or in solution into nanostructures with an oblate spheroidal shape, and corresponding localized surface plasmon resonances features could be tuned. The reshaping nanocrystal strategy can even facilitate the preparation of new classes of plasmonic substrates with gradient or patterned plasmonic properties, which cannot be realized easily using existing lithographic techniques. The substrates with gradient plasmonic properties can serve as platforms for tunable surface-enhanced Raman scattering.
具有可调谐光学特性的等离子体纳米结构及其设计的空间排列可以促进各种应用，从等离子体学到具有空前灵敏度的生物传感器。在这里，我们描述了一种基于金属纳米晶体重塑的制造可调谐等离子体基底的简单而通用的方法。卤化物离子介导的各向异性刻蚀和银原子的再沉积将沉积在二维或三维表面上或溶液中的银纳米棱镜转变为具有扁长球形的纳米结构，并且可以调整相应的局域表面等离子体共振特征。这种重塑纳米晶体的策略甚至可以促进具有梯度或图案化等离子体特性的新型等离子体基底的制备，而这些特性使用现有的光刻技术很难实现。具有梯度等离子体特性的基底可以作为可调谐表面增强拉曼散射的平台。
