Microstructure-based high-Q terahertz metamaterial bio-detection sensor

Abstract

Abstract At present, the sensitivity, accuracy, and stability of terahertz band bio-detection sensors still need to be improved. To meet that demand, a terahertz metamaterial bio-detection sensor was designed and fabricated by introducing a quadruple rotational symmetric microstructure, which can generate strong electromagnetic resonance. The sensor interacts with the incident terahertz wave to generate a magnetic dipole resonance, forming a resonant peak with 98.9% absorption at the resonant frequency of 0.4696 THz. When the refractive index of the analyte increased from 1.0 to 2.0, the resonance peak of the sensor obvious red-shifted, and the absorption of the resonance peak almost exceed 99%. Meanwhile, the sensitivity of the sensor can reach 78.6 GHz/RIU (Refractive index unit, RIU), Q (Quality factor, Q) is up to 55.3, and FOM (Figure of merit, FOM) is up to 9.81. In addition, the quadruple rotation structure unit makes the sensor insensitive to wide incidence angles and polarization. The designed sensor has excellent resonance characteristics and can realize the detection and identification of biomolecules with different refractive indices. It also provides new ideas for the design of terahertz band bio-detection sensors and has important applications in medical diagnosis and real-time monitoring.