Molecular Plasmonics: Single Molecule and Ultrafast Surface-Enhanced Raman Spectroscopy

通过这个项目，化学系的化学测量和成像计划资助西北大学的Richard P.Van Duyne教授探索两种新的光谱技术。其中一个可以检测和识别单个分子，因为它们结合到表面并进行化学反应。另一种可以测量超快时间尺度上的分子结构变化，类似于分子只振动一次。换句话说，我们的目标是拍摄单分子化学行为的分子快照。该项目在促进医疗保健、通信、化学分析和成像等广泛领域的知识方面具有巨大的前景。该项目将为Van Duyne团队的研究生研究人员提供跨学科的培训。该项目的重点是两种新的光谱技术在分子等离子体领域的应用进展。第一种是单分子表面增强拉曼光谱(SMSERS)。目前，SMSERS是唯一一种可以在环境、气体或液体环境中同时检测和识别单个分子的技术。SMSERS将被用来更深入地探索分子和表面之间的基本相互作用。第二种技术是表面增强飞秒受激拉曼光谱(SE-FSRs)。通过系统地研究激光功率依赖、偏振依赖以及激光脉冲与作为衬底的纳米粒子的等离子体激元共振(S)之间的光谱关系，研究SE-FSR的基本光-物质相互作用机制。最终的目标是在化学的固有飞秒时间尺度上探索表面结合分子的反应性。范·杜因的研究项目发展了SERS和相关等离子体光谱学的这一分支学科。这些方法现在是化学、物理、材料科学、生物医学工程和生物学的主要分析工具。该项目力求继续扩大等离子体光谱学在表面科学、灵敏度和时间范围内的化学测量、化学和生物成像、电化学、催化、艺术保护和文化遗产科学方面的影响。

With this project, the Chemical Measurement and Imaging Program of the Chemistry Division is funding Professor Richard P. Van Duyne of Northwestern University to explore two new spectroscopic techniques. One of these can detect and identify individual molecules as they bind to surfaces and chemically react. The other can measure molecular structure changes on ultrafast timescales similar to that for a molecule to vibrate just once. In other words, we are aiming to take molecular snapshots of single molecules doing chemistry. This project has substantial promise to advance knowledge in a broad range of fields including healthcare, communications, chemical analysis and imaging. The project will provide interdisciplinary training for graduate student researchers on the Van Duyne team.This project focuses on advances in the application two new spectroscopic techniques to the field of molecular plasmonics. The first is single molecule surface-enhanced Raman spectroscopy (SMSERS). At present, SMSERS is the only technique that can both detect and identify a single molecule in ambient, gas, or liquid environments. SMSERS will be used to probe more deeply into the fundamental interactions between molecules and surfaces. The second technique is surface-enhanced femtosecond stimulated Raman spectroscopy (SE-FSRS). The fundamental light-matter interaction mechanism of SE-FSRS will be investigated through systematic studies of laser power dependence, polarization dependence, and spectral relations between the laser pulses and the plasmon resonance(s) of the nanoparticles used as substrates. Ultimately the goal is to probe the reactivity of surface bound molecules at the intrinsic femtosecond timescales of chemistry. Van Duyne's research program has developed this subdiscipline of SERS and related plasmonic spectroscopies. These methods are now major analytical tools in chemistry, physics, materials science biomedical engineering, and biology. This project seeks to continue to extend the impact of plasmonic spectroscopy on surface science, chemical measurements at the limits of sensitivity and time scale, chemical and biological imaging, electrochemistry, catalysis, art conservation and cultural heritage science.