CAREER: Surface-Enhanced Nonlinear Spectroscopy: Mapping Electronic Excited States, Probing Surface Adsorbate Structure, and Ultrasensitive Detection

化学测量和成像（CMI）计划的职业奖支持田纳西大学诺克斯维尔的Jon Camden教授开发表面非线性光谱，作为探测分子，表面吸附物结构和超灵敏检测的双光子特性的分析方法。 提出了一种测量绝对SEHRS增强因子的方法，并用于阐明化学增强和电磁增强在SEHRS中各自的作用。分子-等离子体激元耦合和共振增强超拉曼的波长依赖性将提供关于在双光子过程中重要的分子激发态的复杂相互作用的信息。详细的实验和理论之间的比较追求，这将基准新的电子结构方法的非线性分子性质的计算。这些研究将证明SEHRS是一种功能强大、常规适用和超灵敏的分析工具。 此外，这项工作将为未来的表面增强非线性光谱的研究提供基础。除了这项提案的科学目标外，PI还寻求增加在大学攻读科学，技术，工程和数学（STEM）专业的高中生人数。PI将通过创建ASPIRE团队（有抱负的科学家参与研究和教育），为当地公立高中提供课程丰富。 ASPIRE团队将在常规学年期间每月一次向当地高中教室提供动手实验室实验，总共有六项活动。这些活动符合田纳西州课程的要求，并向学生介绍纳米材料的特性。定期评估用于完善活动并衡量其影响。

This CAREER award by the Chemical Measurement and Imaging (CMI) program supports Professor Jon Camden at the University of Tennessee Knoxville to develop surface nonlinear spectroscopy as a analytical method for probing the two-photon properties of molecules, surface adsorbate structure, and ultrasensitive detection. A method for measuring absolute SEHRS enhancement factors is presented and subsequently utilized to elucidate the respective roles of chemical and electromagnetic enhancements in SEHRS. The wavelength dependent nature of the molecule-plasmon coupling and of resonance enhanced hyper-Raman will provide information on the complex interplay of molecular excited states important in two-photon processes. Detailed comparisons between experiment and theory are pursued, which will benchmark new electronic structure methods for the calculation of nonlinear molecular properties. The studies will demonstrate SEHRS to be a powerful, routinely applicable, and ultrasensitive analytical tool. Further, this work will provide the basis for future studies of surface-enhanced nonlinear spectroscopy. In addition to the scientific objectives of this proposal, the PI seeks to increase the number of high-school students pursuing Science, Technology, Engineering, and Mathematics (STEM) majors in college. The PI will collaborate to provide curricular enrichment to local public high-schools through the creation of ASPIRE teams (Aspiring Scientists Participating in Research and Education). ASPIRE teams will deliver hands-on laboratory experiments to local high school classrooms once a month during the regular school year, for a total of six activities. The activities are aligned to meet the requirements of Tennessee State curriculum and introduce students to the properties of nanoscale materials. Regular assessments are used to refine the activities and gauge their impact.