Plasmonically Enhanced Stimulated Coherent Spectroscopy

等离子体增强受激相干光谱

• 批准号: 1609952
• 负责人: Lawrence Ziegler
• 金额: $ 55万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1609952&HistoricalAwards=false
• 关键词: Plasmonically; Enhanced; Stimulated; Coherent; Spectroscopy

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry and the NanoBiosensing Program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems, Professors Ziegler and Reinhard at Boston University merge two very active research areas that have independently already impacted many aspects of our lives; nanomaterials and laser technology. The goal of the project is to exploit the special capabilities afforded by the combination of these two disciplines to advance a technical solution to some important societal needs. More specifically, these researchers explore how ultrafast pulsed laser light interacting with metal nano-materials can be used to enhance and control chemistry on metal surfaces for applications such as chemical catalysis, pollution mitigation, energy conversion, chemical imaging and sensing applications. The on-going experiments develop a detailed description of how molecules interact with nanostructured metal surfaces. Well-established methodologies are already in place that allow the design of nanoscale surfaces with exquisite control. The results of these experiments reveal molecular level details of how these materials interact with molecules and thus provide information on optimizing nanostructures design strategies for the applications cited above. The collaborative nature of this research effort provides participating students with unique experience at the interface of materials and ultrafast science, and thus promote cross-disciplinary activities in science and technology at Boston University. In synergy with the research, this grant supports a substantial education and outreach program to include participation of local Community College students and faculty, inner city and greater Boston area High School students, and High School teachers in conjunction with a newly awarded NSF research experience for undergraduates (REU) site program, as well as other BU based outreach programs.The merger of ultrafast spectroscopy and nanotechnology is being used to study the dynamics and interactions of molecules on plasmonically active surfaces via three ultrafast laser techniques. Plasmonically enhanced (PE) optical heterodyne detected Raman spectroscopy (PE-OHD-RIKES) offers sensitivity advantages for viewing Raman responses on plasmonic surfaces, especially for low frequency modes resulting from molecular-surface physi-adsorption, and a phase sensitive methodology for understanding vibrational and plasmon contributions to nonlinear responses. Analysis of PE three-pulse photon echo peak shift measurements (PE 3PEPS) yields a dynamical description of optical dephasing, or equivalently solvation, of molecules on plasmonic surfaces (inhomogeneous energy distributions, spectral diffusion and fluctuation timescales). Finally, the successful implementation of PE femtosecond stimulated Raman spectroscopy (PE-FSRS), could have enormous impact as a new probe of surface chemistry allowing vibrationally-specific labels to follow the evolution of short-lived intermediates and rapid conformation changes of excited molecules on plasmonic surfaces. Determined dynamical and structural properties of analytes on plasmonic substrates is being contrasted with those of liquid solutions and correlated with observed plasmonic based phenomenon such as SERS enhancement factors. Substrates are being fabricated by a template-guided self-assembly procedure which results in electromagnetically strongly coupled nanoparticle cluster arrays where optical fields are enhanced by both near field coupling between nanoparticles, and diffractive coupling between clusters. Detailed molecular level information about how molecules interact with engineered plasmonic surfaces is providing rational design strategies for maximizing plasmon enhancement of optical responses and chemical outcomes. The implementation of this methodology is impactful upon optical imaging capabilities in terms of improved sensitivity and faster acquisition times, real time monitoring of photoinduced surface chemical reactivity, enhanced chemical and biological sensing capabilities, and improved strategies for subsequent spontaneous SERS and other plasmonic based techniques.

在化学，生物工程，环境和运输系统的化学测量和成像计划的支持下，波士顿大学的Ziegler和Reinhard教授合并了两个非常活跃的研究领域，这些研究领域已经独立地影响了我们生活的许多方面；纳米材料和激光技术。 该项目的目的是利用这两个学科的结合提供的特殊能力，以提高技术解决方案，以满足某些重要的社会需求。 更具体地说，这些研究人员探讨了如何使用与金属纳米材料相互作用的超快速脉冲激光如何用于增强和控制金属表面上的化学，以用于化学催化，缓解污染，能量转换，化学成像和传感应用。正在进行的实验对分子如何与纳米结构金属表面相互作用进行了详细描述。已经建立了完善的方法，可以设计具有精美控制的纳米级表面。 这些实验的结果揭示了这些材料如何与分子相互作用的分子水平细节，从而提供了有关优化纳米结构设计策略的信息。这项研究工作的协作性质为参与的学生提供了材料和超快科学界面的独特经验，从而促进了波士顿大学科学技术方面的跨学科活动。 为了与研究协同作用，该赠款支持一项实质性的教育和外展计划，包括当地社区大学生和教职员工，内城和大波士顿地区高中生，以及高中教师，以及与新授予的NSF研究经验的NSF研究经验（REU）的现场计划（REU）网站计划，以及其他BU基于BU基础的iS Ontrach Ondyress。分子通过三种超快激光技术在血浆活性表面上的相互作用。 血浆增强的（PE）光学杂种检测到的拉曼光谱（PE-OHD-RIKES）具有敏感性的优势，可以在等离子表面上查看拉曼反应，尤其是对于由分子表面物理吸附而引起的低频模式，以及一种相位敏感的方法，可用于了解纤维化和等立纤维组成和等位基因对非单元的贡献。 PE三脉冲光子回声峰值偏移测量值（PE 3PEP）的分析得出了分子在等离子表面上分子的光学去效应或等效溶剂化的动态描述（不均匀能量分布，光谱扩散和波动时间表）。最后，成功实施了PE飞秒刺激的拉曼光谱（PE-FSR），作为表面化学的新探针，可以产生巨大的影响，从而允许振动特异性的标记跟随短暂寿命的中间体的演变，并遵循等离子表面上激发分子的快速构象变化。分析物在等离子体底物上确定的动力学和结构特性与液体溶液的形成对比，并与观察到的基于等离激子的现象（如SERS增强因子）相关。底物是通过模板引导的自组装程序制造的，该程序导致电磁强烈耦合的纳米颗粒群集阵列，其中通过纳米颗粒之间的近场耦合以及簇之间的衍射耦合来增强光场。 有关分子如何与工程等离子体表面相互作用的详细分子水平信息正在提供合理的设计策略，以最大程度地提高等离子体的光学响应和化学结果的增强。这种方法的实施对光学成像能力的影响是在提高灵敏度和更快的获取时间，对光诱导的表面化学反应性的实时监测，增强的化学和生物传感能力的实时监测，以及改善了随后自发SERS和其他基于等离子的技术的策略。