The SERS activity of a supported ag nanocube strongly depends on its orientation relative to laser polarization
The SERS activity of a supported ag nanocube strongly depends on its orientation relative to laser polarization
复制标题
DOI：
10.1021/nl070157q
复制
发表时间：
2007-04-01
期刊：
影响因子：
10.8
通讯作者：
Xia, Younan
中科院分区：
文献类型：
--
作者：
McLellan, Joseph M.;Li, Zhi-Yuan;Xia, Younan
合成了具有尖锐角或截角的银纳米立方体，将其沉积在硅基底上，并使用具有拉曼活性的硫醇进行功能化，以用于表面增强拉曼散射（SERS）研究。使用带有对准标记的基底使我们能够将单个纳米立方体的SERS光谱与其通过高分辨率扫描电子显微镜成像所揭示的物理参数相关联。我们观察到当纳米立方体相对于激发激光的偏振方向以不同角度取向时，SERS强度会发生巨大变化。当纳米立方体被截断且外形接近球形时，这种角度依赖性就不太显著。采用数值计算来证实我们的观察结果，并将变化的根源归因于不同激光偏振之间近场分布的差异。
Silver nanocubes with sharp or truncated corners were synthesized, deposited on silicon substrates, and functionalized with Raman-active thiols for surface-enhanced Raman scattering (SERS) studies. The use of substrates with registration marks allowed us to correlate the SERS spectra from individual nanocubes to their physical parameters revealed by high-resolution SEM imaging. We observed dramatic variations in SERS intensity when the nanocubes were oriented at different angles relative to the polarization of excitation laser. This angular dependence was less significant when the nanocubes were truncated and became nearly spherical in profile. Numerical calculations were employed to confirm our observations, and to attribute the source of variation to the difference in near-field distribution between different laser polarizations.