Electrically-connected plasmonic metamaterials for capture and detection of CTC

描述(由申请人提供)：迫切需要开发可靠和准确的方法来检测和识别循环中低浓度的肿瘤细胞(CTCs)。特别吸引人的是可以在服务点实施的全血样本中CTCs的检测。血液中极少量的四氯化碳构成了巨大的技术挑战，阻碍了直接检测，并需要在任何传感/诊断测量之前分离/浓缩四氯化碳。纳米技术的最新进展使得能够将分离/浓缩和传感/诊断功能结合在一个实体中。我们计划的总体目标是开发一个简单但准确的全血样本CTCs检测平台，将CTCs的选择性捕获与其独特的光谱指纹图谱相结合。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)，使用了一种新的基于超材料的等离子体平台：FANO共振不对称超材料(FRAMM)。不同的基于FRAMM的红外“像素”将被调谐到不同的红外频率，从而实现与传感器相连的目标细胞的空间定位。为了提高靶细胞与传感器连接的特异性和稳健性，所有FRAMM像素都将由一系列抗体功能化。细胞与底物的结合将使用差异反射率FTIR进行询问 光谱学不仅将检测结合事件，而且还将产生高度特异的细胞指纹。将使用主成分分析对光谱数据集进行分析，以区分不同的目标单元并检测其空间位置。FRAMM将提供50-100 nm的场穿透到细胞内，确保对整个细胞膜进行光谱探测。通过将电连接的FRAMM结合到AC电极中，我们将使用细胞特异性介电(DEP)来极大地丰富传感器表面相对于全血样本中丰富得多的血细胞的肿瘤细胞数量。细胞特异性DEP将通过用分子特异性二氧化硅包裹的等离子体纳米棒标记CTCs来完成，从而大大提高CTCs相对于血细胞的交流极化能力。捕获的肿瘤细胞将通过以下方式与血细胞进一步区分开来 他们固有的独特的红外指纹，以及通过Nanoro标签的振动指纹。纳米棒既可以作为红外造影剂，也可以作为细胞特异性介电泳膜的载体。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的无标记鉴定，以及(B)在单一设备中对罕见肿瘤细胞进行稳健的浓缩/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.