Advances in Metasurface-Based Terahertz Sensing

Terahertz (THz) technology has attracted significant attention because of its unique applications in biological/chemical sensing, medical imaging, non-invasive detection, and high-speed communication. Metasurfaces provide a dynamic platform for THz sensing applications, showcasing greater flexibility in design and the ability to optimize light-matter interactions for specific target enhancements, which includes enhancing the intramolecular and intermolecular vibration modes of the target biological/chemical molecules, setting them apart from conventional approaches. This review focuses on recent THz metasurface sensing methods, including metasurfaces based on toroidal dipole and quasi-bound states in the continuum to improve sensing sensitivity, nanomaterial-assisted metasurfaces for specific recognition, and metasurfaces combined with microfluidic with reduce water absorption loss. Furthermore, the applications of THz metasurface sensing is reviewed, including detecting the concentration of biomolecules, cells, tissues, and microbes, THz biomolecular fingerprint absorption spectra recognition, and identifying chiral compounds using chiral and achiral metasurfaces. Finally, the prospects for the next generation of THz sensors are examined.