Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
Nano Lett. 2012 Mar 14;12(3):1424-30. doi: 10.1021/nl2041063. Epub 2012 Jan 31.
The plasmon coupling between a Au nanorod and a small Au nanosphere has been studied with scattering measurements, electrodynamic simulations, and model analysis. The spatial perturbation of the nanosphere leads to distinct spectral changes of the heterodimer. The plasmonic responses, including Fano resonance, are remarkably sensitive to the nanosphere position on the nanorod, the gap distance, and the nanocrystal dimensions. The nanosphere dipole is intriguingly found to rotate around the nanorod dipole to achieve favorable attractive interaction for the bonding dipole-dipole mode. The sensitive spectral response of the heterodimer to the spatial perturbation of the nanosphere offers an approach to designing plasmon rulers of two spatial coordinates for sensing and high-resolution measurements of distance changes.
利用散射测量、电动力学模拟和模型分析研究了金纳米棒和小金纳米球之间的等离子体耦合。纳米球的空间微扰导致杂化二聚体的光谱发生明显变化。等离子体响应，包括 Fano 共振，对纳米球在纳米棒上的位置、间隙距离和纳米晶体尺寸非常敏感。有趣的是，纳米球偶极子被发现绕纳米棒偶极子旋转，以实现有利于键合偶极子-偶极子模式的吸引力相互作用。杂化二聚体对纳米球空间微扰的敏感光谱响应为设计两个空间坐标的等离子体标尺提供了一种方法，用于传感和距离变化的高分辨率测量。
