Multiparametric Optical Microbe Sensing with Engineered Photonic-Plasmonic Nanostructures

纳米粒子组件产生了不同于那些孤立粒子的新特性，因此，为在纳米尺度上创造新能力提供了巨大的机会。这个提议试图利用这样一个事实，即金纳米颗粒阵列具有可工程的等离子体共振，其空间和频率分布可以通过阵列的形态来控制。由于贵金属纳米粒子的精确等离子体共振波长取决于环境的折射率，纳米结构的贵金属表面是比色传感器。非周期金属纳米结构维持结构颜色模式，使基于空间相关成像的全新传感方法成为可能。此外，由纳米颗粒团簇组装而成的纳米结构表面可以有效地定位入射电磁场并产生高电磁场增强。因此，纳米颗粒簇阵列也是表面增强拉曼光谱的极好衬底。本研究旨在结合纳米结构表面的光子和等离子体特性，开发多参数响应器，通过对弹性和非弹性光散射过程的综合分析，实现增强的光学微生物检测和识别性能。本项目的研究将开发一种新型的多参数光学微生物传感器，由于后续的两个传感阶段，该传感器可以实时高保真地识别和检测各种微生物（病毒、细菌、孢子）。特异性的第一阶段将通过传感器表面的抗体功能化来实现。微生物与这些抗体的结合将通过弹性散射光的比色位移来检测。在第二个分析步骤中，对弹性散射光进行分析以获得微生物表面的振动SERS谱。该光谱可作为微生物的指纹，并可与多变量数据分析和适当的文库光谱相结合进行识别。我们期望基于SERS的鉴定方法能够在菌株水平上对微生物进行分类。与传统光学生物传感器相比，所提出的两个后续识别阶段的方法显著提高了识别可靠性。由于SERS允许在单细胞水平上识别生物体，因此提出的多参数传感器可以为光学分析生物体铺平道路。现实世界吗?样品中总是含有复杂的微生物混合物。除了这些重要的传感进展之外，本提案中的研究还将提高当前设计具有明确光学响应的光子等离子体贵金属结构的能力。更广泛、可靠和快速的微生物检测与环境监测、食品质量控制和国土安全等关键传感领域有关。所提出的传感器可以使光学微生物检测更快、更可靠，从而可以影响上述所有传感领域。除了概述的科学影响外，该研究还具有明确的教育和推广成分。该项目将为高中生、本科生和研究生提供参与合作研究和教育项目的机会。它将构成至少两篇博士论文的基础。在与实验室研究的协同作用下，该提案将使一个实质性的推广计划成为可能。首席研究员（PI）每年为来自当地内城高中的学生组织一次纳米夏令营，PI和联合PI都赞助本科生和感兴趣的高中生在这个跨学科的研究工作中获得实践研究经验。这些外联活动将有助于激发初级研究人员和高中生对生物传感和一般科学技术领域的热情。

ReinhardCBET-1159552Nanoparticle assemblies generate new properties that are different from those of the isolated particles and, therefore, offer tremendous opportunities for creating new capabilities on the nanoscale. This proposal seeks to take advantage of the fact that defined arrays of gold nanoparticles have engineerable plasmon resonances whose spatial and frequency distribution can be controlled through the morphology of the array. Since the exact plasmon resonance wavelength of a noble metal nanoparticles depend on the refractive index of the environment, nanostructured noble metal surfaces are colorimetric sensors. Aperiodic metal nanostructures sustain structural color patterns which enable entirely new sensing approaches based on spatial correlation imaging. In addition, nanostructured surfaces assembled from nanoparticle clusters as building blocks can efficiently localize incident electromagnetic fields and generate high E-field enhancements. Consequently, nanoparticle cluster arrays are also superb substrates for surface enhanced Raman spectroscopy. This proposal seeks to combine the advantageousphotonic and plasmonic properties of nanostructured surfaces to develop multiparametric responders that achieve enhanced optical microbe detection and identification performance through combined analysis of elastic and inelastic light scattering processes.Intellectual MeritsThe research in this project will develop a new class of multiparametric optical microbe sensors, that can identify and detect a broad range of microbes (viruses, bacteria, spores) with high fidelity due to two subsequent sensing stages in real time. A first stage of specificity will be achieved through antibody functionalization of the sensor surface. Binding of microbes to these antibodies will be detected through a colorimetric shift in the elastically scattered light. In the second analysis step in elastically scattered light is analyzed to obtain a vibrational SERS spectrum of the microbe surface. This spectrum serves as a fingerprint of the microbe and enables its identification when combined with multivariate data analysis and appropriate library spectra. We anticipate that the SERS based identification approach will enable microbe classifications on the strain level. The proposed approach of two subsequent identification stages achieves a significant improvement in the identification reliability over conventional optical biosensors. Because SERS allows an identification of organisms on the single cell level, the proposed multiparametric sensors could pave the way to an optical analysis of ?real world? samples that always contain a complex mixture of microbes. Besides these important sensing advances, the research in this proposal will also improve current capabilities to engineer photonic-plasmonic noble metal structures with defined optical responses.Broader ImpactReliable and rapid microbe detection is relevant in critical sensing areas such as environmental monitoring, food quality control, and homeland security. The proposed sensor could make optical microbe detection faster and more reliable and could thus impact all of the above sensing areas. In addition to the outlined scientific impacts, the research has clear educational and outreach components. The project will offer high school, undergraduate, and graduate students the opportunity to participate in a collaborative research and education program. It will form the basis for at least two PhD theses. In synergy with the laboratory research, this proposal will enable a substantial outreach program. The Principal Investigator (PI) organizes an annual NanoCamp for students from local inner city high schools, and both PI and Co-PI sponsor undergraduate students and interested high school students to obtain hands-on research experience in this interdisciplinary research effort. These outreach activities will help to enthuse junior researchers and high school students for the field of biosensing and science and technology in general.