Angle-multiplexed all-dielectric metasurfaces for broadband molecular fingerprint retrieval

Date

2019

Authors

Leitis, Aleksandrs
Tittl, Andreas
Liu, Mingkai
Lee, Bang Hyun
Gu, Man Bock
Kivshar, Yuri
Altug, Hatice

Journal Title

Journal ISSN

Volume Title

Publisher

American Association for the Advancement of Science

Abstract

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.

Description

Keywords

Citation

Source

Science Advances

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC)

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