Selective detection enabled by terahertz spectroscopy and plasmonics: Principles and implementations

Speedy and selective detection of sensing targets is of great interest to researchers from diverse fields. Dominated by excitations of intramolecular and intermolecular vibrations, the emerging terahertz (THz) spectroscopy offers both molecular fingerprint information and biosensing abilities, which is excellent for speedy and selective sensing applications. In this review, we focus on THz selective sensing principles and introduce three frequently utilized methods enabled by THz fingerprints, the interaction between THz absorption of molecules and plasmonic resonances, and THz metamaterial biosensors. The recent progress of THz selective sensing implementations including detections of gas molecules, solid molecules, protein, nucleic acid, cells, and viruses are also summarized. We note that current THz sensing research is multidisciplinary and has led cross-disciplinary collaborations between physics and bioscience. The acceleration of THz selective sensing will realize plenty practical THz applications and achieve outstanding improvements.