Rapid and quantitative immunoassay for multiplexed and highly sensitive point-of-care diagnostics using rationally designed, self-assembled, SERS-active 3D superstructures

个性化医疗的点式诊断需要快速、定量、多路和灵敏的检测方案。目前检测蛋白质的金标准是酶联免疫吸附试验(EL ISA)，它需要多个耗时的洗涤步骤，通过酶反应进行信号放大，并且仅限于一种颜色，灵敏度有限。这项建议的中心目标是开发一种新的快速和定量免疫分析平台，用于多重和高灵敏度的护理点诊断，使用表面增强拉曼散射(SERS)纳米标记/标记与磁珠和微流控相结合，捕获目标蛋白质并避免洗涤步骤。三维SERS活性玻璃涂层超结构作为新型的SERS纳米标记/标记将通过金卫星在金纳米棒核心上的自组装来合成。用于分析的最佳SERS活性3D超结构的选择将由经验结构-活性关联和计算机模拟相结合来指导。细胞因子作为一类与临床相关的生物标志物将被用作一个模型系统，用于在便携式配置中建立基于SERS的磁珠/微流控免清洗免疫分析，用于医疗诊断。我们的目的是展示5种不同细胞因子在飞秒到大气压浓度下的快速和同时检测。这种分析方法普遍适用于其他目标分子，只需简单地交换磁性和SERS纳米颗粒上的相应配体。

Point-of-care diagnostics for personalized medicine requires rapid, quantitative, multiplexed and sensitive detection schemes. The current gold standard of immunoassays for protein detection is ELISA (enzyme-linked immuno-sorbent assay), which requires multiple time-consuming washing steps, signal amplification via the enzyme reaction and is restricted to one color with only limited sensitivity. The central aim of this proposal is to develop a novel platform for rapid and quantitative immunoassays for multiplexed and highly sensitive point-of-care diagnostics using surface-enhanced Raman scattering (SERS) nanotags/labels in combination with magnetic beads and microfluidics for capturing the target proteins and avoiding washing steps. 3D SERS-active glass-coated superstructures as novel SERS nanotags/labels will be synthesized via self-assembly of gold satellites on a gold nanorod core. The choice of optimal SERS-active 3D superstructures for use in assays will be guided by empirical structure-activity correlations in combination with computer simulations. Cytokines as a clinically relevant class of biomarkers will be used as a model system for establishing the SERS-based magnetic bead/microfluidic no-wash immunoassay in a portable configuration for point-of-care diagnostics. We aim at demonstrating the rapid and simultaneous detection of 5 different cytokines at femto- to attomolar concentrations. This analytical method is universally applicable to other target molecules by simply exchanging the corresponding ligands on the magnetic and SERS nanoparticles.