Ultrasensitive Label-Free Flow Detector via Surface Enhanced Raman Scattering

描述（由申请人提供）：本提案的目标是创建一种超灵敏、化学特异性、无标记的拉曼检测，以表征生物液体中发现的微粒（MP）。这些颗粒来源于细胞， 疾病病理学，但挑战目前的调查方法。我们的方法建立在我们实验室的初步结果基础上，表明我们可以检测溶液中的单个脂质体。来自我们的纳米结构表面的表面增强拉曼散射（Sers）提供信号增强，从而实现颗粒识别。通过将微尺度流体学与纳米技术相结合，我们将创建一个超灵敏的检测器，可以耦合到现有的分离设备。该方案的具体目标是：1）在原型检测器中优化使用流体动力学聚焦的高效Sers检测。2)证明区分脂质囊泡样品作为MP模型系统的能力。3)将流量检测器与毛细管电泳分离器连接，以分析复杂混合物。该提案将开发技术，验证性能，并展示分析生物样品的实用性。我们将研究从细胞培养系统中获得的MP，以证明这种方法的有效性。这项研究将产生能够在超低浓度下进行化学表征的仪器，可能是单颗粒水平。

DESCRIPTION (provided by applicant): The goal of this proposal is to create an ultrasensitive, chemical-specific, label-free Raman detection to enable characterization of microparticles (MPs) found in biological fluids. The particles derive from cells and are diagnostic of disease pathology, but challenge current methods of investigation. Our approach builds from initial results in our laboratory showing that we can detect individual liposomes in solution. Surface enhanced Raman scattering (SERS) from our nanostructured surface provides signal enhancements that enable particle identification. By combining microscale fluidics with nanotechnology, we will create an ultrasensitive detector that can be coupled to existing separation equipment. The specific aims of this proposal are: 1) Optimize high-efficiency SERS detection using hydrodynamic focusing in a prototype detector. 2) Demonstrate the ability to distinguish lipid vesicle samples as a model system for MPs. 3) Couple the flow detector to a capillary electrophoresis separation to analyze a complex mixture. The proposal will develop the technology, validate performance, and demonstrate utility to analyze a biological sample. We will study MPs obtained from a cell culture system to prove the efficacy of this approach. This research will produce instrumentation capable of chemical characterization at ultralow concentrations, potentially the single particle level.