Development of closely-coupled nanostructures for advanced sensing and imaging

拟议的研究项目旨在开发紧密耦合的纳米粒子组件作为光学传感器，用于生物医学研究、医疗保健和安全领域未满足的需求。基于单等离子体纳米结构的传感对于阐明微环境中的生物分子相互作用是非常宝贵的；然而，到目前为止，由于无法获得定制的研究级仪器设置，演示仅限于概念验证研究。提出的工作旨在通过设计生物可编程的自下而上自组装纳米颗粒簇来克服这一缺点。这些等离子体组件表现出增强的光散射，从而可以从暗场显微镜图像中平行推断数千个传感器的光学响应。目标是开发和评估单细胞水平的生物分析传感平台，并建立微环境中分子分布和化学梯度的空间制图能力。具体而言，本研究旨在开发新型生物分子连接体、新型多功能纳米颗粒和大面积复用传感贴片来实现这一目标。在第一个研究领域，我们将基于核酸及其与多肽的杂交偶联物设计新的生物分子连接体，以提高等离子体组装对生物标志物（如microRNA和蛋白质）的响应性。将从单细胞中检测生物分子，以验证该技术在分析生物标志物的细胞分布方面的适用性。在第二个研究领域，我们将开发一类新的纳米粒子组件，包括荧光的正交光学性质和局部表面等离子体共振。结合新开发的生物分子连接物，多功能组件将集成到一个强大的大面积柔性传感贴片中，以实现现场或护理点应用的多路检测。提出的传感平台对比了现有的单细胞分析技术和分子成像技术，这些技术需要大型仪器，集中实验室和样品制备，这是费力和昂贵的。通过开发便携式，经济和用户友好的传感平台，否则只能在研究环境中进行分析，我们的工作将有助于弥合基础研究和实际应用之间的差距。

The proposed research program aims to develop closely-coupled nanoparticle assemblies as optical sensors for the unmet needs in biomedical research, healthcare and security. Sensing based on single plasmonic nanostructure is shown to be invaluable for elucidating biomolecular interactions in the microenvironment; however demonstrations have thus far been limited to proof-of-concept studies because of the inaccessibility of the customized research-grade instrumentation setups. The proposed work aims to overcome this drawback by designing bioprogrammable bottom-up self-assembled nanoparticle clusters. These plasmonic assemblies exhibit enhanced light scattering to enable the extrapolation of the optical response of thousands of sensors in parallel from darkfield microscopy images. The objectives are to develop and evaluate the sensing platform for bioanalysis down to the single-cell level, and to establish the capability of spatial mapping of molecular distribution and chemical gradient in the microenvironment. Specifically, the proposed research aims to develop new biomolecular linkers, novel multifunctional nanoparticles and large-area multiplexed sensing patch to reach the goals. In the first research area, we will design new biomolecular linkers based on nucleic acids and their hybrid conjugates with peptides for imparting responsivity of the plasmonic assemblies to biomarkers such as microRNA and proteins. The detection of biomolecules from single cells will be pursued to verify the applicability of the technology in analyzing the cellular distribution of biomarkers. In the second research area, we will develop a new class of nanoparticle assemblies comprising orthogonal optical properties of fluorescence and localized surface plasmon resonance. In combination with the newly developed biomolecular linkers, the multifunctional assemblies will be integrated into a robust large-area flexible sensing patch to enable multiplexed detection for field or point-of-care applications. The proposed sensing platform contrasts existing single-cell analytical technologies and molecular imaging techniques which require large instrumentations, centralized laboratory and sample preparation that is laborious and costly. By developing portable, economical and user-friendly sensing platform for analyses that otherwise could only be carried out in research settings, our work will help bridge the gap of fundamental research and practical applications.