School of Applied and Engineering Physics, Cornell University, Ithaca, New York, 14853, USA.
Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, 10021, USA.
Lab Chip. 2023 May 2;23(9):2228-2240. doi: 10.1039/d3lc00017f.
Fourier transform infrared (FTIR) spectroscopy is a popular technique for the analysis of biological samples, yet its application in characterizing live cells is limited due to the strong attenuation of mid-IR light in water. Special thin flow cells and attenuated total reflection (ATR) FTIR spectroscopy have been used to mitigate this problem, but these techniques are difficult to integrate into a standard cell culture workflow. In this work, we demonstrate that the use of a plasmonic metasurface fabricated on planar substrates and the probing of cellular IR spectra through metasurface-enhanced infrared spectroscopy (MEIRS) can be an effective technique to characterize the IR spectra of live cells in a high-throughput manner. Cells are cultured on metasurfaces integrated with multiwell cell culture chambers and are probed from the bottom using an inverted FTIR micro-spectrometer. To demonstrate the use of MEIRS as a cellular assay, cellular adhesion on metasurfaces with different surface coatings and cellular response to the activation of the protease-activated receptor (PAR) signaling pathway were characterized through the changes in cellular IR spectra.
傅里叶变换红外（FTIR）光谱学是一种分析生物样本的常用技术，但由于水中中红外光的强烈衰减，其在活细胞特征分析中的应用受到限制。特殊的薄流动池和衰减全反射（ATR）FTIR 光谱学已被用于减轻这个问题，但这些技术难以集成到标准细胞培养工作流程中。在这项工作中，我们证明了在平面衬底上制造的等离子体超表面以及通过表面增强红外光谱学（MEIRS）探测细胞的红外光谱可以是一种有效的技术，可用于高通量方式对活细胞的红外光谱进行特征分析。细胞在集成有多孔细胞培养腔的超表面上进行培养，并通过倒置的 FTIR 微光谱仪从底部进行探测。为了证明 MEIRS 作为细胞分析的用途，通过细胞在具有不同表面涂层的超表面上的粘附以及细胞对蛋白酶激活受体（PAR）信号通路激活的反应，通过细胞红外光谱的变化对其进行了表征。
