Quantitative Measurement of Surface Plasmon-Enhanced Electromagnetic Fields on Single Plasmonic Nanostructures

美国佛罗里达大学化学系大分子、超分子和纳米化学计划的魏大卫教授正在开发方法和策略，以便在单纳米粒子水平上直接和定量地评估表面等离子体共振(SPR)增强的电磁场(EM)的大小。这些方法可以绘制出各向异性纳米结构表面“热点”的横向空间分布，进而可以在纳米尺度上深入研究各个热点的局域消光分布、偏振相关性和超快激发态动力学。为了显著促进对纳米局域热点的本质和起源的理解，正在对局部纳米结构几何形状和由此产生的局域SPR的属性之间的精确关联进行详细的分析。长期目标是极大地促进新型等离子体纳米材料的开发，这些材料的性能针对生物医学和太阳能领域的应用进行了优化，包括单分子传感和太阳能催化。拟议项目的发现旨在开发新的等离子体纳米材料和技术，促进公共健康和清洁能源，这两个方面对国家的未来至关重要。该项目更广泛的教育影响是对生物医学传感和太阳能生产领域的下一代科学家的指导和启发。魏教授和他的团队正在特别关注扩大科学界代表性不足的群体的参与。与学生辅导和课程开发相结合，魏教授积极参与持续的外展活动，教育高中生、教师和普通公众有关等离子体纳米材料的知识。

Prof. Wei David Wei at the University of Florida is being supported by the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry in developing methods and strategies for a direct and quantitative evaluation of the magnitude of surface plasmon resonance (SPR)-enhanced electromagnetic (EM) fields at the single-nanoparticle level. These methods are to allow the mapping of the lateral spatial distribution of "hot spots" on the surfaces of anisotropic nanostructures and, furthermore, to permit a thorough investigation into the local extinction profiles, polarization dependences, and ultra-fast excited state dynamics of individual hot spots at the nanometer scale. A detailed analysis of the precise correlation between local nanostructure geometry and the attributes of the resulting localized SPR is being made in order to significantly advance the understanding of the nature and origin of nano-localized hot spots. The long-range objective is to greatly facilitate the development of new classes of plasmonic nanomaterials with properties optimized for applications in the biomedical and solar energy fields, including single-molecule sensing and solar photocatalysis.Discoveries from the proposed project are targeted at the development of new plasmonic nanomaterials and technologies that promote public health and clean energy, both vital to the nation's future. The broader educational impact of this program is to be the instruction and inspiration of the next generation of scientists in biomedical sensing and solar energy production. Prof. Wei and his group are specifically focusing on broadening the participation of groups underrepresented in the sciences. In conjunction with student mentorship and curriculum development, Prof. Wei is active in ongoing outreach activities to educate high school students, teachers, and the general public on plasmonic nanomaterials.