Tech4Health Institute, New York University Langone Health, New York, NY 10016, United States of America.
Department of Radiology, New York University Langone Health, New York, NY 10016, United States of America.
Nanotechnology. 2023 Jul 19;34(40). doi: 10.1088/1361-6528/ace117.
In the past decades, nanophotonic biosensors have been extended from the extensively studied plasmonic platforms to dielectric metasurfaces. Instead of plasmonic resonance, dielectric metasurfaces are based on Mie resonance, and provide comparable sensitivity with superior resonance bandwidth, Q factor, and figure-of-merit. Although the plasmonic photothermal effect is beneficial in many biomedical applications, it is a fundamental limitation for biosensing. Dielectric metasurfaces solve the ohmic loss and heating problems, providing better repeatability, stability, and biocompatibility. We review the high-Q resonances based on various physical phenomena tailored by meta-atom geometric designs, and compare dielectric and plasmonic metasurfaces in refractometric, surface-enhanced, and chiral sensing for various biomedical and diagnostic applications. Departing from conventional spectral shift measurement using spectrometers, imaging-based and spectrometer-less biosensing are highlighted, including single-wavelength refractometric barcoding, surface-enhanced molecular fingerprinting, and integrated visual reporting. These unique modalities enabled by dielectric metasurfaces point to two important research directions. On the one hand, hyperspectral imaging provides massive information for smart data processing, which not only achieve better biomolecular sensing performance than conventional ensemble averaging, but also enable real-time monitoring of cellular or microbial behaviour in physiological conditions. On the other hand, a single metasurface can integrate both functions of sensing and optical output engineering, using single-wavelength or broadband light sources, which provides simple, fast, compact, and cost-effective solutions. Finally, we provide perspectives in future development on metasurface nanofabrication, functionalization, material, configuration, and integration, towards next-generation optical biosensing for ultra-sensitive, portable/wearable, lab-on-a-chip, point-of-care, multiplexed, and scalable applications.
在过去的几十年中，纳米光子生物传感器已经从广泛研究的等离子体平台扩展到介电超表面。介电超表面不是基于等离子体共振，而是基于米氏共振，提供可比的灵敏度，具有更高的共振带宽、Q 因子和品质因数。虽然等离子体光热效应在许多生物医学应用中是有益的，但它是生物传感的一个基本限制。介电超表面解决了欧姆损耗和加热问题，提供了更好的重复性、稳定性和生物相容性。我们综述了基于元原子几何设计定制的各种物理现象的高 Q 共振，并比较了介电超表面和等离子体超表面在折射计、表面增强和手性传感等各种生物医学和诊断应用中的性能。除了传统的使用光谱仪进行光谱位移测量，基于成像和无光谱仪的生物传感技术也得到了强调，包括单波长折射计条码、表面增强分子指纹图谱和集成可视化报告。介电超表面实现的这些独特模式指向两个重要的研究方向。一方面，高光谱成像提供了大量的信息，用于智能数据处理，不仅比传统的集合平均实现更好的生物分子传感性能，而且能够在生理条件下实时监测细胞或微生物的行为。另一方面，单个超表面可以集成传感和光学输出工程的功能，使用单波长或宽带光源，提供简单、快速、紧凑和具有成本效益的解决方案。最后，我们对超表面纳米制造、功能化、材料、结构和集成提供了未来发展的展望，以期实现下一代超灵敏、便携式/可穿戴、片上实验室、即时检测、多重和可扩展的光学生物传感应用。
