Development of Novel-Scheme Tip-Enhanced Raman Spectroscopy and Its Application in Realistic Conditions -- Photochemistry of MoS2

新型尖端增强拉曼光谱的研制及其实际应用——MoS2的光化学

基本信息

批准号：
1905043
负责人：
Zhenrong Zhang
金额：
$ 40.5万
依托单位：
Baylor University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2025-08-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905043&HistoricalAwards=false
关键词：
Development Novel Scheme Tip Enhanced

项目摘要

Scanning probe microscopy methods that provide chemical maps of the surface of objects hold promise for revealing information that is useful for making chemical reactions more efficient and developing faster electronic and optical devices. Scanning probe microscopes may one day yield chemical images of individual molecules in a variety of environments, but this potential to visualize such small objects has been stymied due to limitations associated with effectively and simply integrating the probe element into the microscope system. With support from the Chemical Measurement and Imaging Program and partial co-funding from the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professors Zhenrong Zhang and Howard Lee at Baylor University are developing tip-enhanced Raman spectroscopy techniques that allow for imaging of individual nanometer-sized objects in their native environments, as a result of novel, integrated fiber optic probe tips made by sophisticated microfabrication methods. This new approach to building chemical imaging systems significantly simplifies microscope operation and yields a method for visualizing tiny amounts of sample. The Baylor team readily investigates chemical reactions on catalyst surfaces in gas and liquid environments. Due to the practical and accessible nature of the new nanoscale chemical imaging tool, the research may impact research in materials, biomedical, and optoelectronic sciences. Professors Zhang and Lee are providing undergraduate and technical college students new learning and research opportunities in optics and scanning probe microscopy. Such student skill sets are valuable for the students' future careers. The Baylor team is also providing broad, public education and outreach to the Waco community through frequent hands-on optics and spectroscopy events at the Mayborn Museum. This project develops a user-friendly, tip-enhanced, Raman spectroscopy nanoscale chemical imaging system that is based on an optical alignment-free design, namely, an integrated plasmonic fiber-tip assembly. The fiber-tip assembly can be easily integrated into existing scanning probe microscope designs. This unique approach provides a simple path for independent delivery of excitation light to and collection of light from a sample, which offers high light coupling efficiency and virtually nonexistent far-field background interference. As a result, sample signals are highly sensitive and provide detection limits approaching that of single molecules. The plasmonic nanostructured optical fibers merge the fields of plasmonics and fiber optics, thereby enabling tip-enhanced Raman spectroscopy imaging applications in numerous gaseous and liquid environments. The specific objectives of this proposal are to demonstrate nanoscale mapping using fiber-tip-enhanced Raman spectroscopy imaging and study the photochemistry of molybdenum sulfide (MoS2) at the nanometer scale in a controlled ambient pressure environment. The team also seeks to demonstrate fiber-tip-enhanced Raman spectroscopy imaging in a liquid environment via the use of field-tunable plasmonic materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

提供物体表面化学图的扫描探针显微镜方法有望揭示有助于使化学反应更有效并开发更快的电子和光学设备的信息。扫描探针显微镜有一天可能会在各种环境中产生单个分子的化学图像，但由于与有效且简单地将探针元件集成到显微镜系统相关的限制，这种可视化如此小物体的潜力受到阻碍。在化学测量和成像项目的支持以及化学系高分子、超分子和纳米化学项目的部分共同资助下，贝勒大学的张振荣教授和霍华德·李教授正在开发尖端增强拉曼光谱技术，该技术可以对由于采用先进的微加工方法制成的新型集成光纤探针尖端，使得单个纳米尺寸的物体能够在其自然环境中生存。这种构建化学成像系统的新方法显着简化了显微镜操作，并提供了一种可视化微量样品的方法。贝勒团队很容易研究气体和液体环境中催化剂表面的化学反应。由于新型纳米级化学成像工具的实用性和易用性，这项研究可能会影响材料、生物医学和光电科学的研究。张教授和李教授为本科生和技术学院的学生提供光学和扫描探针显微镜方面新的学习和研究机会。这样的学生技能对学生未来的职业生涯很有价值。贝勒团队还通过在梅伯恩博物馆频繁举办光学和光谱实践活动，向韦科社区提供广泛的公共教育和宣传活动。该项目开发了一种用户友好的、尖端增强的拉曼光谱纳米级化学成像系统，该系统基于免光学对准设计，即集成等离子体光纤尖端组件。光纤尖端组件可以轻松集成到现有的扫描探针显微镜设计中。这种独特的方法提供了一条简单的路径，用于独立地将激发光传输到样品并从样品收集光，从而提供高光耦合效率和几乎不存在的远场背景干扰。因此，样品信号高度灵敏，检测限接近单分子。等离激元纳米结构光纤融合了等离激元学和光纤光学领域，从而能够在多种气体和液体环境中实现尖端增强拉曼光谱成像应用。该提案的具体目标是使用光纤尖端增强拉曼光谱成像演示纳米级绘图，并在受控环境压力环境下研究纳米级硫化钼 (MoS2) 的光化学。该团队还寻求通过使用场可调等离子体材料在液体环境中演示光纤尖端增强拉曼光谱成像。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的评估进行评估，被认为值得支持。影响审查标准。