Angle-multiplexed all-dielectric metasurfaces for broadband molecular fingerprint retrieval
Angle-multiplexed all-dielectric metasurfaces for broadband molecular fingerprint retrieval
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DOI：
10.1126/sciadv.aaw2871
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发表时间：
2019-05-01
期刊：
影响因子：
13.6
通讯作者：
Altug, Hatice
中科院分区：
文献类型：
--
作者：
Leitis, Aleksandrs;Tittl, Andreas;Altug, Hatice
红外光谱通过检测分子的特征振动指纹来解析分子的结构。亚波长光限制和纳米光子增强已经扩展了这种技术用于单层研究的范围。然而，目前的方法仍然需要复杂的光谱设备或可调谐光源。在这里，我们介绍了一种新的基于超颖表面的方法，用于在宽光谱范围内检测分子吸收指纹，该方法将最先进的角度扫描折射传感器的设备级简单性与红外光谱的化学特异性相结合。具体来说，我们开发了锗基高Q超颖表面，能够在1100和1800 cm（-1）之间提供多种光谱选择性和表面敏感的共振。我们使用这种方法来检测不同的相互作用的分析物，包括蛋白质，适体，和聚赖氨酸不同的吸收签名。结合宽带非相干照明和检测，我们的方法将每个入射角的全反射信号与分子吸收的强度相关联，从而实现了紧凑的角度扫描配置中的无光谱仪操作，非常适合现场部署应用。
Infrared spectroscopy resolves the structure of molecules by detecting their characteristic vibrational fingerprints. Subwavelength light confinement and nanophotonic enhancement have extended the scope of this technique for monolayer studies. However, current approaches still require complex spectroscopic equipment or tunable light sources. Here, we introduce a novel metasurface-based method for detecting molecular absorption fingerprints over a broad spectrum, which combines the device-level simplicity of state-of-the-art angle-scanning refractometric sensors with the chemical specificity of infrared spectroscopy. Specifically, we develop germanium-based high-Q metasurfaces capable of delivering a multitude of spectrally selective and surface-sensitive resonances between 1100 and 1800 cm(-1). We use this approach to detect distinct absorption signatures of different interacting analytes including proteins, aptamers, and polylysine. In combination with broadband incoherent illumination and detection, our method correlates the total reflectance signal at each incidence angle with the strength of the molecular absorption, enabling spectrometer-less operation in a compact angle-scanning configuration ideally suited for field-deployable applications.