Wackenhut Frank, Failla Antonio Virgilio, Meixner Alfred J
Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tuebingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
Anal Bioanal Chem. 2015 May;407(14):4029-34. doi: 10.1007/s00216-015-8642-1. Epub 2015 Apr 9.
In this paper, we explain in detail the wavelength dependence of the elastic scattering pattern of individual, optically isolated gold nanorods by using confocal microscopy in combination with higher order laser modes, i.e., radially/azimuthally polarized laser modes. We demonstrate that the spectral dependence of the scattering pattern is mostly caused by the relative strength of the gold nanorods' plasmonic modes at different wavelengths. Since the gold nanorods' plasmonic modes are determined by the particles' geometrical parameter, e.g., size and aspect ratio, as well as the refractive index of the surrounding medium, we show that the spectral dependence of the scattering pattern is a simple, not invasive way to determine, e.g., the gold nanorod aspect ratio or physical variation of the local environment. Thus, a further development of spectral imaging of gold nanorods can lead to the employment of this technique in biomedical assays involving also living samples.
在本文中，我们通过结合共聚焦显微镜与高阶激光模式（即径向/方位角偏振激光模式），详细解释了单个光学隔离的金纳米棒弹性散射图案的波长依赖性。我们证明，散射图案的光谱依赖性主要由金纳米棒在不同波长下的等离子体模式的相对强度引起。由于金纳米棒的等离子体模式由粒子的几何参数（例如尺寸和纵横比）以及周围介质的折射率决定，我们表明散射图案的光谱依赖性是一种简单、非侵入性的方法，可用于确定例如金纳米棒的纵横比或局部环境的物理变化。因此，金纳米棒光谱成像的进一步发展可导致该技术在涉及活体样本的生物医学检测中的应用。
