Spatial-dispersioned nonlocal metasurfaces with angular interrogation: An efficient alternative to surface plasmon resonances for the characterization of bio-molecule interactions

作者：Yuyun Bi, Yuechun Shi, Zhanghua Han · 发表于：APL Photonics · 年份：2025 · DOI：10.1063/5.0253249 · 被引用次数：5 · 研究领域：Plasmonic and Surface Plasmon Research、Metamaterials and Metasurfaces Applications、Orbital Angular Momentum in Optics

Recent progress in nonlocal photonic modes within all-dielectric metasurfaces has established them as a promising alternative to traditional surface plasmon resonance technique for real-time monitoring of molecular interactions with high sensitivity. However, current implementations rely on optical spectroscopy to detect spectral changes, leading to expensive instrumentation. Here, we introduce an innovative approach that leverages the high-Q quasi-guided modes (QGMs) within all-dielectric nonlocal metasurfaces, utilizing angular interrogation as the detection mechanism. The pronounced spatial dispersion profile of the QGM allows for the detection of refractive index variations through the resonant angle of incidence. This method simplifies the detection process, using a simple continuous wave laser, thus eliminating the need for costly optical spectroscopy setups. Our experimental validation, conducted using a dimerized-hole photonic crystal slab, demonstrates effective characterization of the streptavidin–biotin binding interaction with remarkable sensitivity, detecting streptavidin with a threshold of less than 0.1 nM. This showcases the potential of our approach in molecular sensing applications.