Development of closely-coupled nanostructures for advanced sensing and imaging

拟议的研究计划旨在开发紧密耦合的纳米颗粒组件作为光学传感器，以满足生物医学研究、医疗保健和安全方面的未得到满足的需求。基于单一等离子体纳米结构的传感被证明对于阐明微环境中的生物分子相互作用是非常有价值的；然而，迄今为止，由于无法获得定制的研究级仪器装置，示范仅限于概念验证研究。这项拟议的工作旨在通过设计生物可编程的自下而上的自组装纳米颗粒簇来克服这一缺陷。这些等离子组件表现出增强的光散射，能够从暗场显微镜图像中并行推断数千个传感器的光学响应。其目标是开发和评估生物分析的传感平台，并建立微环境中分子分布和化学梯度的空间映射能力。 具体地说，该研究旨在开发新的生物分子连接物、新型多功能纳米颗粒和大面积多路复用传感贴片来实现这一目标。在第一个研究领域，我们将设计基于核酸及其与多肽的杂化结合的新型生物分子连接物，以赋予血浆组装对microRNA和蛋白质等生物标记物的响应性。将继续从单个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装，包括荧光的正交光学性质和局域表面等离子体共振。与最新开发的生物分子连接体相结合，多功能组件将被集成到一个坚固的大面积灵活传感贴片中，以实现现场或护理点应用的多路检测。拟议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、集中化的实验室和费力且昂贵的样品制备。通过开发便携式、经济和用户友好的传感平台，进行原本只能在研究环境中进行的分析，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.