Theory of Chiral Plasmonic Nanostructures Comprising Metal Nanocrystals and Chiral Molecular Media
Theory of Chiral Plasmonic Nanostructures Comprising Metal Nanocrystals and Chiral Molecular Media
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DOI：
10.1002/cphc.201100958
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发表时间：
2012-07-16
期刊：
影响因子：
2.9
通讯作者：
Fan, Zhiyuan
中科院分区：
文献类型：
--
作者：
Govorov, Alexander O.;Fan, Zhiyuan
等离子体纳米晶体通过电场和磁场与手性分子壳层强烈相互作用，并以这种方式获得新的手性光学性质。手性从生物分子到等离子体共振的转移是一种集体现象，并且强烈依赖于纳米结构的几何形状。分子手性壳层中的集体效应可能会抑制或增强等离子体圆二色性（CD），这取决于杂化壳层的几何形状。在大型手性等离子体结构中，我们确定了一种新的等离子体CD电动力学机制，它与我们先前描述的等离子体手性的近场偶极机制有质的不同。我们的模型还表明，各向异性纳米晶体（例如纳米棒或定向分子壳）在等离子体频率下具有强烈增强的CD。本文提出并模拟的一类手性等离子体纳米结构可用于设计新的光学介质和手性传感器。
Plasmonic nanocrystals strongly interact with chiral molecular shells through electric and magnetic fields and in this way acquire new chiro-optical properties. Transfer of chirality from biomolecules to the plasmonic resonances is a collective phenomenon and strongly depends on the geometry of nanostructure. Collective effects in a molecular chiral shell may suppress or enhance plasmonic circular dichroism (CD) depending on the geometry of hybrid nanocrystal. In large chiral plasmonic structures, we identify a new electrodynamic mechanism of plasmonic CD that is qualitatively different to the near-field, dipolar mechanism of the plasmonic chirality described by us previously. Our models also show that anisotropic nanocrystals, such as nanorods or oriented molecular shells, have strongly enhanced CD at the plasmonic frequency. A family of chiral plasmonic nanostructures proposed and modeled here can be used for designing new optical media and chiral sensors.