Emerging metasurfaces for refractometric sensing: fundamental and applications

Metasurfaces are designed to introduce strong light matter interactions by anomalously manipulating the properties of light at subwavelength scale, which have been employed to enhance performances in various sensing techniques, such as chiral sensing, surface-enhanced spectroscopy, and infrared absorption, among others. In recent decades, the label-free metasurface based refractometric sensor has been an active research field for biosensing, chemical sensing and gas sensing, owing to its non-invasive nature, real-time characterization and convenient operation principle, which significantly suppress the potential contamination to target species compared to other sensing methods (e.g. fluorescence sensing). In this review, we briefly discuss the recent advances on metasurface refractometric sensors, including their physical principles, device structures and characterizations, and focus on their associated applications in biochemical and gas sensing.