Light-Directed Synthesis of Metal Nanocrystal Dimers for Scalable Precision Plasmonics

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，加州大学欧文分校的Matthew Law博士正在开发将金属纳米粒子对连接在一起形成二聚体的方法。纳米颗粒之间的小间隙可以集中光线，这可能会带来重大的技术影响。然而，科学家们仍然缺乏好的合成方法来制造它们。劳博士和他的学生们一起，利用光来保护溶液中形成的纳米粒子对。该方法旨在生产比现有方法纯度更高、结构控制更好、数量更大的二聚体。从长远来看，这些基础研究可能会导致更好的催化剂和化学传感器，以及这些纳米颗粒的新的生物医学应用。该项目还促进STEM教育，并为来自历史上高等教育参与水平较低背景的低收入学生提供学习机会和丰富知识。胶体等离子体金属纳米晶体（NCs）在光谱的可见和近红外区域（例如金和银纳米晶体）具有强的和可调谐的局部表面等离子体共振（LSPRs），对光-物质相互作用的基础研究有很大的兴趣。该项目正在开发一种新的光导方法，用于单锅，可扩展合成单分散，可调谐和功能性金属NC二聚体，有望克服以前方法的局限性。通过原位和非原位吸收光谱和非原位透射电子显微镜（TEM）监测了合成过程。所得到的NC二聚体预计具有优异的结构单分散性和稳定性，可调和可接近的热点，以及其他特性，使它们非常适合加速等离子体化学和物理的进展。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program in the Division of Chemistry, Dr. Matthew Law at the University of California, Irvine is developing methods to link pairs of metal nanoparticles together to form dimers. The small gap between the nanoparticles can concentrate light, which could provide significant technological impact. However, scientists still lack good syntheses for making them. Working with his students, Dr. Law is using light to protect the nanoparticle pairs as they form in a solution. This method aims to produce dimers with higher purity, better control over structure and in larger quantities than is possible using existing methods. These fundamental studies could lead to better catalysts and chemical sensors, and new biomedical applications of these nanoparticles in the long term. The project also promotes STEM education and provides academic opportunities and enrichment to low-income students from backgrounds with historically low levels of participation in higher education. Colloidal plasmonic metal nanocrystals (NCs) that possess strong and tunable localized surface plasmon resonances (LSPRs) in the visible and near-infrared regions of the spectrum (e.g., gold and silver NCs) are of great interest for fundamental studies of light-matter interactions. This project is developing a novel light-directed method for the one-pot, scalable synthesis of mono-disperse, tunable, and functional metal NC dimers that promises to overcome the limitations of previous approaches. The synthesis is monitored by in situ and ex situ absorption spectroscopy and ex situ transmission electron microscopy (TEM). The resulting NC dimers are expected to have excellent structural mono-dispersity and stability, tunable and accessible hot spots, and other characteristics that make them well-suited for accelerating progress in plasmonic chemistry and physics.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.