Ultrahigh Sensitive Terahertz Metasurface with 2D MoS₂ for Refractive Index Biosensing

Terahertz (THz) metasurfaces possess extensive advantages for biosensing with their unique terahertz spectral signatures. Developing terahertz metasurfaces with ultrahigh sensitivity requires enhanced Q-factor for improved performance and functionality. High Q-factor resonance enhances the light-matter interaction for biosensing by exciting high order plasmonic modes. In this work, we demonstrate a methodology for increasing the Q-factor resonance of a polarization insensitive Electromagnetically Induced Transparency-like (EIT) terahertz metasurface by an addition of a 2D Molybdenum disulfide (MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) layer. Our simulation results show a doubling of Q factor from 4.8 to 8.45 and an improved theoretical sensitivity of 661 GHz/RIU with respect to the metasurface at a resonant frequency of 2.02 THz. Our results prove the enhancement of Q-factor and the sensitivity of terahertz metasurface with the incorporation of 2D MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> layer which will serve as an excellent platform for protein biosensing applications.