Surface Enhanced Raman Bbiosensors for Biomedical Applications

拉曼光谱是测量分子振动量子的有力工具，其产生的光谱提供了独特的化学指纹。在含有数千个不同分子的复杂生物医学基质中，振动光谱可以用来区分不同的生化样品。此外，与特定分子相关的拉曼光谱的强度与其浓度成正比，因此允许同时定量。拉曼光谱的主要缺陷是信号弱，每107个入射光子中只有不到1个是拉曼散射的。我们团队的总体研究目标是基于申请人的空芯光子晶体光纤(HC-PCF)拉曼系统创建紧凑、快速和高灵敏度的护理点诊断平台。这一愿景得到了三个相辅相成的目标的支持：1.功能性纳米颗粒的开发，包括a)创建一系列可用于表面增强拉曼散射的功能化金属纳米颗粒，这些纳米颗粒可用于临床相关生物或分子的特定传感，以及b)开发同时提供磁浓缩、生物识别和局部表面等离子共振增强的纳米颗粒。这两个目标进一步发展了两种不同的表面增强拉曼散射方法：基于固有的原位光谱特征对分析物进行直接表面增强拉曼散射检测，以及基于生物识别分离的分析物的表面增强拉曼散射检测。2.发展用于拉曼光谱处理的机器学习技术，改进机器学习模型，提取用于生化分析的特征，并加快模型生成。3.拉曼系统的小型化，以部署护理点光谱诊断系统。必须减少传统自由空间光谱仪的占地面积以及填充HC-PCF的流体成分。为了实现这一目标，大量的机械部件将被微流控部件取代，同样，自由空间光学部件将被使用超材料的集成光学部件取代。这项研究计划将进一步加深我们对纳米光子学和纳米材料的集体知识，并将在生物医学工程和光子学领域取得一些进展。我们的主要目标之一是开发用于疾病/感染的固有多路复用快速光谱检测的设备。这些设备的成功实施将带来更快的诊断周转时间、更快的治疗时间和更好的临床结果。还将获得有关金属纳米颗粒的性质和合成、超材料的纳米光子行为以及生物材料的振动光谱的基本科学知识。

Raman spectroscopy is a powerful tool for measuring vibrational quanta of molecules, wherein the resultant spectra provides unique chemical fingerprint. In complex biomedical matrices with thousands of different molecules, vibrational spectroscopy can be used to differentiate between biochemically distinct samples. Furthermore, the intensity of the Raman bands associated with a certain molecule are proportional to its concentration, thus allowing for simultaneous quantification. The major limitation of Raman spectroscopy is its weak signal, less than 1 in 107 incident photons are Raman scattered. Our group's overarching research goal is to create a compact, rapid, and highly sensitive point-of-care diagnostic platform based on the applicant's hollow-core photonic crystal fiber (HC-PCF) Raman system. This vision is supported by three complimentary objectives: 1.Functional nanoparticle development which include a) creating families of functionalized metal nanoparticles for surface enhanced Raman scattering that are amenable to specific sensing of clinically relevant organisms or molecules, and b) developing nanoparticles which provide simultaneous magnetic enrichment, biorecognition, and local surface plasmon resonance enhancement. These two objectives further two distinct surface enhanced Raman scattering methodologies; direct surface enhanced Raman scattering detection of analytes based on intrinsic in-situ spectral characteristics, and surface enhanced Raman scattering detection based on analyte isolated by biorecognition. 2.Advance the machine learning techniques used to process Raman spectra, improve machine learning models, extract features for biochemical analyses, and expedite model generation. 3.Miniaturization of Raman system to deploy a point-of-care spectral diagnostic system. The footprint of the conventional free-space spectrometer as well as the fluidic components that fill the HC-PCF must be reduced. To achieve this, bulk mechanical parts will be replaced by microfluidic equivalents, and similarly, free-space optics will be replaced by integrated optical components using metamaterials. This research program will further our collective knowledge on nanophotonics and nanomaterials and will lead to several advances in the fields of biomedical engineering and photonics. One of our principal aims is the development of devices for inherently multiplexed rapid spectral detection of diseases/ infections. Successful implementation of such devices will lead to faster diagnostic turnaround times, prompt administration of treatment, and better clinical outcomes. Fundamental scientific knowledge on the properties and synthesis of metal nanoparticles, the nanophotonic behavior of metamaterials, and the vibrational spectra of biological materials will also be gained.