Anisotropic Etching of Silver Nanoparticles for Plasmonic Structures Capable of Single-Particle SERS
Anisotropic Etching of Silver Nanoparticles for Plasmonic Structures Capable of Single-Particle SERS
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DOI：
10.1021/ja906954f
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发表时间：
2010-01-13
影响因子：
15
通讯作者：
Yang, Peidong
中科院分区：
文献类型：
--
作者：
Mulvihill, Martin J.;Ling, Xing Yi;Yang, Peidong
随着新的且更复杂的纳米结构被发现，对于发生在金属纳米粒子几何边界表面的局域表面等离子体激元（LSPs）的理解不断深入。已经表明，金属 - 电介质界面处电子的振荡强烈依赖于纳米粒子的尺寸、对称性和间距。在此，我们提出一种通过使用高度各向异性蚀刻工艺化学控制银纳米晶体形状的新方法。对蚀刻剂强度和反应条件的调节能够以高产率和高纯度制备新的纳米粒子形状，这是常规纳米晶体生长方法无法合成的。蚀刻过程产生粒子内间隙，其引入了修正的等离子体特性以及在近红外区域显著的散射强度。这些新的银粒子是波长可调谐的单粒子表面增强拉曼光谱（spSERS）的优良基底。
The understanding of the localized surface plasmons (LSPs) that occur at the geometrically bounded surface of metal nanoparticles continues to advance as new and more complex nanostructures are found. It has been shown that the oscillation of electrons at the metal dielectric interface is strongly dependent on the size, symmetry, and proximity of nanoparticles. Here, we present a new method to chemically control the shape of silver nanocrystals by using a highly anisotropic etching process. Tuning of the etchant strength and reaction conditions allows the preparation of new nanoparticle shapes in high yield and purity, which cannot be synthesized with conventional nanocrystal growth methods. The etching process produces intraparticle gaps, which introduce modified plasmonic characteristics and significant scattering intensity in the near-infrared. These new silver particles serve as excellent substrates for wavelength-tunable, single-particle surface enhanced Raman spectroscopy (spSERS).