3D Nanostar Dimers with a Sub-10-nm Gap for Single-/Few- Molecule Surface-Enhanced Raman Scattering
3D Nanostar Dimers with a Sub-10-nm Gap for Single-/Few- Molecule Surface-Enhanced Raman Scattering
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DOI：
10.1002/adma.201304553
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发表时间：
2014-04-01
影响因子：
29.4
通讯作者：
Di Fabrizio, Enzo
中科院分区：
文献类型：
--
作者：
Chirumamilla, Manohar;Toma, Andrea;Di Fabrizio, Enzo
在过去的几年里，为了检测高度稀释的液体中的分子，和/或记录位于“热点”处的单个或几个分子的拉曼光谱，制造用于极大电场增强的纳米结构变得越来越重要。一种流行且具有成本效益的方法涉及具有随机分布热点的表面，例如，可以通过在基底上沉积等离子纳米颗粒或通过金属膜的沉积后处理来获得。[1]一种补充策略依赖于热点的受控工程[2]及其通过自上而下的方法制造。自上而下方法的优点包括i）制造的可再现性，ii）场增强的均匀性，以及iii）热点的位置、尺寸和形状的高度可控性。然而，由于在制造中通常采用电子束或离子束技术的事实，折衷是高的制造成本和少量的热点。然而，工程结构的表面增强拉曼光谱（Sers）是非常适合单/少数分子检测，因为它们能够检测在一个明确的点，例如，在一个扫描探针针尖，或在一个位置，分子可以被引导，如超疏水基板上的工程缺陷证明。[3]第一章
The fabrication of nanostructures for extremely large electricfield enhancement has become increasingly important over the last few years with the aim to detect molecules in highly diluted liquids, and/or to record the Raman spectra of a single or a few molecules located at a “hot spot”. One popular and cost-effective approach involves surfaces with a random distribution of hot spots, which can be obtained, for example, by the deposition of plasmonic nanoparticles on substrates or via post-deposition treatment of metal films.[1] A complementary strategy relies on the controlled engineering of hot spots [2] and their fabrication via top–down methods. The advantages of the top–down methods include i) the reproducibility of the fabrication, ii) the uniformity in the field enhancement, and iii) the high controllability of the position, size, and shape of the hot spots. The trade-offs, however, are high fabrication costs and the small number of hot spots, as a result of the fact that electron-or ion-beam techniques are typically employed in the fabrication. Nevertheless, engineered structures for surfaceenhanced Raman spectroscopy (SERS) are highly appropriate for single-/few-molecule detection because they enable detection at a well-defined spot—for example, on a scanning probe tip, or at a position to which the molecules can be directed, as demonstrated by engineered defects on superhydrophobic substrates.[3]