Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany.
Chemphyschem. 2012 Mar;13(4):952-8. doi: 10.1002/cphc.201100718. Epub 2012 Feb 29.
We investigated the influence of the orientation of individual gold nanorods on the polarization-dependent single-particle surface-enhanced Raman spectroscopy (SERS) of adenine. Higher-order laser beams (radial and azimuthal polarizations) have been used in combination with a parabolic mirror-assisted confocal optical microscope. Based on the photoluminescence (PL) patterns of the single gold nanorods and the simulated electric-field distribution in the focus, we distinguished between isolated gold rods and clusters as well as single nanorods with different orientations. We found that for single gold nanorods lying flat on the substrate, the longitudinal particle plasmon resonance (PPR) mode can be excited more efficiently with the in-plane field component in the focus of an azimuthally polarized laser beam, which enables the observation of stronger enhanced adenine Raman spectra from the single gold nanorods compared to the case of a radially polarized beam.
我们研究了单个金纳米棒的取向对腺嘌呤的偏振相关单粒子表面增强拉曼光谱（SERS）的影响。高阶激光束（径向和角向偏振）与抛物面镜辅助共焦显微镜结合使用。基于单个金纳米棒的光致发光（PL）模式和焦点处的模拟电场分布，我们区分了孤立的金棒和簇以及具有不同取向的单个纳米棒。我们发现，对于平放在基底上的单个金纳米棒，在角向偏振激光束的焦点中，可以更有效地激发纵向粒子等离激元共振（PPR）模式，这使得与径向偏振光束的情况相比，能够从单个金纳米棒中观察到更强的增强腺嘌呤拉曼光谱。
