John-Herpin Aurelian, Tittl Andreas, Kühner Lucca, Richter Felix, Huang Steven H, Shvets Gennady, Oh Sang-Hyun, Altug Hatice
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland.
Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany.
Adv Mater. 2023 Aug;35(34):e2110163. doi: 10.1002/adma.202110163. Epub 2022 Nov 1.
Infrared spectroscopy provides unique information on the composition and dynamics of biochemical systems by resolving the characteristic absorption fingerprints of their constituent molecules. Based on this inherent chemical specificity and the capability for label-free, noninvasive, and real-time detection, infrared spectroscopy approaches have unlocked a plethora of breakthrough applications for fields ranging from environmental monitoring and defense to chemical analysis and medical diagnostics. Nanophotonics has played a crucial role for pushing the sensitivity limits of traditional far-field spectroscopy by using resonant nanostructures to focus the incident light into nanoscale hot-spots of the electromagnetic field, greatly enhancing light-matter interaction. Metasurfaces composed of regular arrangements of such resonators further increase the design space for tailoring this nanoscale light control both spectrally and spatially, which has established them as an invaluable toolkit for surface-enhanced spectroscopy. Starting from the fundamental concepts of metasurface-enhanced infrared spectroscopy, a broad palette of resonator geometries, materials, and arrangements for realizing highly sensitive metadevices is showcased, with a special focus on emerging systems such as phononic and 2D van der Waals materials, and integration with waveguides for lab-on-a-chip devices. Furthermore, advanced sensor functionalities of metasurface-based infrared spectroscopy, including multiresonance, tunability, dielectrophoresis, live cell sensing, and machine-learning-aided analysis are highlighted.
红外光谱通过解析生物化学系统中组成分子的特征吸收指纹，提供有关其组成和动力学的独特信息。基于这种固有的化学特异性以及无标记、非侵入性和实时检测的能力，红外光谱方法在从环境监测、国防到化学分析和医学诊断等众多领域开启了大量突破性应用。纳米光子学通过使用共振纳米结构将入射光聚焦到电磁场的纳米级热点，极大地增强光与物质的相互作用，在推动传统远场光谱的灵敏度极限方面发挥了关键作用。由这种谐振器规则排列组成的超表面进一步增加了在光谱和空间上定制这种纳米级光控制的设计空间，这使其成为表面增强光谱学的宝贵工具包。从超表面增强红外光谱的基本概念出发，展示了用于实现高灵敏度超表面器件的各种谐振器几何形状、材料和排列，特别关注声子和二维范德华材料等新兴系统，以及与用于芯片实验室设备的波导的集成。此外，还强调了基于超表面的红外光谱的先进传感器功能，包括多共振、可调性、介电电泳、活细胞传感和机器学习辅助分析。
