Plasmonic Substrates for High Performance SPR Detection in the Kretschmann Configuration

在化学系化学测量与成像计划和生物基础设施部生物研究仪器开发计划的支持下，加州大学河滨分校的全成教授和他的研究小组正在开发使用表面等离子体共振(SPR)方法检测生物分子的新材料。SPR是一种测量类型，其中从金属表面反射的光或从纳米尺度的金属颗粒散射的光可以提供关于发生在金属表面的分子或化学反应的信息。基于表面等离子体共振的生物传感技术为研究分子相互作用提供了有效的工具，促进了对生物化学以及药物发现等相关领域的理解。本研究利用Kretschmann组态研究了衬底中传播的表面等离子体激元(SPP)与局域表面等离子体的耦合。一些结构，如排列的纳米棒和纳米空洞被用来产生新的平台，以改善耦合，从而提高检测性能。这项工作的具体目标包括：1)发展等离子体纳米颗粒薄膜和二维周期性纳米结构作为增强无标记分析的SPR衬底；2)在Au衬底上发展有序多孔膜以诱导强烈的光学/等离子体耦合，从而提高SPR检测；3)将新开发的SPR衬底应用于涉及膜蛋白和传感的分子相互作用的分析。还将探索LDI-MS底物分析，以系统评价芯片上正交检测的范围和实用性。这一研究项目的高度跨学科性质也提供了不同的机会，学生可以从中获得处理表面化学、纳米技术、光学和生物分析化学中的不同问题的经验。

Supported by the Chemical Measurement and Imaging Program in the Division of Chemistry, and the Instrument Development for Biological Research Program in the Division of Biological Infrastructure, Professor Quan Cheng and his research group at the University of California-Riverside are developing new materials for the detection of biomolecules using surface plasmon resonance (SPR) methods. SPR is a type of measurement where the light reflected from a metal surface or scattered from metal particles of nanometer dimensions can provide information about the molecules or chemical reactions occuring at the metal surface. SPR-based biosensing technology provides effective tools for study of molecular interactions, facilitates the understanding of biological chemistry, and related fields such as drug discovery. This research focuses on coupling of propagating surface plasmon polaritons (SPPs) and localized surface plasmons in the substrate using the Kretschmann configuration. Several structures such as aligned nanorods and nanovoids are employed to generate new platforms to improve the coupling and thus the detection performance. Specific goals of the research in this work include: 1) developing plasmonic nanoparticle films and 2-D periodic nanostructures as SPR substrates for enhanced label-free analysis; 2) developing ordered porous films on the Au substrate to induce strong optical/plasmonic coupling that improves SPR detection; 3) applying the newly developed SPR substrates for analysis of molecular interactions that involve membrane proteins and aptasensing. LDI-MS analysis with the substrates will be explored as well to systematically evaluate the scope and pragmatism of on-chip orthogonal detection. The highly interdisciplinary nature of this research program also offers diverse opportunities from which students can gain experience when dealing with different problems in surface chemistry, nanotechniques, optics and bioanalytical chemistry.