Biophotonics: Near-field Raman Microscopy of Biological Membranes

这个项目的目标是探索一种新的方法来提高光学显微镜和光谱学的空间分辨率。将开发的仪器有望更深入地了解嵌入在复杂环境中的纳米结构的功能，例如生物膜中的单个蛋白质。提出了一种基于表面增强拉曼散射效应的高分辨率近场光学显微镜。在这项技术中，一个锋利的贵金属尖端被紧靠在样品表面上。适当偏振的激光照射尖端，并在尖端诱导出较强的表面电荷密度。这导致了激发场的增强。严格的计算表明，尖端的光场强度可以比激发激光的强度提高3-4个数量级。尖端的增强场实现了与样品表面的高度局域光学相互作用，从而产生了拉曼信号，从而产生了就在尖端下方的样品区域的振动光谱。

0086368NovotnyThe objective of this project is to explore a new methodology to increase the spatial resolution of optical microscopy and spectroscopy. The instrument to be developed holds promise for gaining deeper insight into the functionality of nanometric structures embedded in complex environments such as single proteins in biological membranes.It is propose to develop a high resolution near-field optical microscope based on the effect of surface enhanced Raman scattering. In this technique, a sharp noble metal tip is held in close proximity over the sample surface. Properly polarized laser light illuminates the tip and induces a strong surface charge density at the tip. This leads to an enhancement of the exciting laser field. Rigorous calculations show that the intensity of the optical fields at the tip can be enhanced by 3 - 4 orders of magnitude over the intensity of the exciting laser light. The enhanced field at the tip enables a highly localized optical interaction with the sample surface thereby generating a Raman signal and thus a vibrational spectrum of the sample area right beneath the tip.