Electrically-connected plasmonic metamaterials for capture and detection of CTC

描述（由申请人提供）：迫切需要开发检测和鉴定低浓度循环肿瘤细胞（CTC）的可靠且准确的方法。特别有吸引力的是可以在服务点实施的全血样品中CTC的检测。血液中非常小丰度的CTC构成了巨大的技术挑战，阻止了直接检测，并且在任何感测/诊断测量之前需要CTC分离/富集。纳米技术的最新进展使得能够将分离/富集和传感/诊断功能结合在单个实体中。我们计划的总体目标是开发一种简单但准确的检测平台，用于从全血样品中检测CTC，该平台将联合收割机选择性捕获CTC与其独特的光谱指纹相结合。 我们的方法是基于肿瘤细胞膜的表面增强红外吸收光谱（SEIRAS），使用一种新的基于超材料的等离子体平台：Fano共振非对称超材料（FRAMATERIALS）。不同的基于FRAMM的红外“像素”将被调谐到不同的红外频率，从而使附着在传感器上的目标细胞的空间定位成为可能。为了提高靶细胞附着到传感器的特异性和鲁棒性，所有FRAMM像素将由一系列抗体功能化。细胞与基质的结合将使用差反射率FTIR进行询问 这将是一个新的技术，它不仅可以检测结合事件，而且还可以产生高度特异性的细胞指纹。光谱数据集将使用主成分分析进行分析，以区分不同的目标细胞，并检测其空间位置。FRAC 10将提供50- 100 nm的场穿透进入细胞，确保整个细胞膜被光谱询问。 通过将电连接的FRAMEX结合到AC电极中，我们将使用细胞特异性介电电泳（DEP）来极大地富集传感器表面上的肿瘤细胞群体，相对于全血样品中丰富得多的血细胞。细胞特异性DEP将通过用分子特异性二氧化硅涂覆的等离子体纳米棒标记CTC来实现，从而大大增加CTC相对于血细胞的AC极化率。捕获的肿瘤细胞将进一步与血细胞区分， 他们的天然独特的红外指纹，以及通过纳米标签的振动指纹。纳米棒将既作为红外对比剂，又作为细胞特异性介电电泳的输送载体。所提出的方法结合了以下优点：（a）使用FRAMM-SEIRAS对肿瘤细胞进行高灵敏度的无标记鉴定，以及（B）在单个装置中对罕见肿瘤细胞进行稳健的富集/分离机制。

DESCRIPTION (provided by applicant): There is an urgent need to development reliable and accurate methods of detection and identification of low concentrations of circulating tumor cells (CTCs). Especially attractive would be detection of CTCs in whole blood samples that can be implemented at the point of service. Very small abundances of CTCs in blood pose a tremendous technological challenge, preventing direct detection and necessitating CTC isolation/enrichment prior to any sensing/diagnostic measurement. Recent advances in nanotechnology enable combining the isolation/enrichment and sensing/diagnostic functions in a single entity. The overall goal of our program is to develop a simple but accurate detection platform for CTCs from whole blood samples that will combine selective capturing of CTCs with their unique spectroscopic fingerprinting. Our approach is based on surface-enhanced infrared absorption spectroscopy (SEIRAS) of tumor cell membranes using a new metamaterial-based plasmonic platform: Fano-resonant Asymmetric Metamaterials (FRAMMs). Different FRAMM-based infrared "pixels" will be tuned to different infrared frequencies, thereby enabling spatial localization of the target cells attached to the sensor. To improve the specificity and robustness of target cell's attachment to the sensor, all FRAMM pixels will be functionalized by a range of antibodies. Cell's binding to the substrate will be interrogated using difference-reflectivity FTIR spectroscopy that will not only detect binding events, but will also yield highly specific cell fingerprints. Spectroscopic data sets will be analyzed using principal component analysis to differentiate between different target cells and to detect their spatial location. FRAMMs will provide field penetration of 50-100nm into the cell, ensuring that the entire cellular membrane is spectrally interrogated. By combining electrically connected FRAMMs into an AC electrode, we will use cell-specific dielectrophoresis (DEP) to greatly enrich the population of tumor cells on the sensor surface with respect to blood cells that are much more abundant in whole blood samples. Cell-specific DEP will be accomplished by labeling CTCs with molecular-specific silica-coated plasmonic nanorods, thereby greatly increasing the AC polarizability of CTCs with respect to blood cells. Captured tumor cells will be further distinguished from blood cells through their native distinct IR fingerprint, as well as through the vibrational fingerprints of the nanoro labels. The nanorods will serve as both infrared contrast agents and as delivery vehicles for cell-specific dielectrophoresis. The proposed approach combines the advantages of (a) highly-sensitive label-free identification of tumor cells using FRAMM-SEIRAS, and (b) robust enrichment/isolation mechanism for rare tumor cells in a single device.