Sensitivity-Tunable Terahertz Liquid/Gas Biosensor Based on Surface Plasmon Resonance with Dirac Semimetal

In this paper, we study the sensitivity-tunable terahertz (THz) liquid/gas biosensor in a coupling prism-three-dimensional Dirac semimetal (3D DSM) multilayer structure. The high sensitivity of the biosensor originates from the sharp reflected peak caused by surface plasmon resonance (SPR) mode. This structure achieves the tunability of sensitivity due to the fact that the reflectance could be modulated by the Fermi energy of 3D DSM. Besides, it is found that the sensitivity curve depends heavily on the structural parameters of 3D DSM. After parameter optimization, we obtained sensitivity over 100 & DEG;/RIU for liquid biosensor. We believe this simple structure provides a reference idea for realizing high sensitivity and a tunable biosensor device.

Automated summary

In this paper, a sensitivity-tunable terahertz (THz) liquid/gas biosensor based on a coupling prism-three-dimensional Dirac semimetal (3D DSM) multilayer structure is studied. The high sensitivity of the biosensor is attributed to the sharp reflected peak caused by surface plasmon resonance (SPR) mode. The reflectance of the biosensor can be modulated by the Fermi energy of 3D DSM, resulting in tunable sensitivity. After parameter optimization, the sensitivity of the liquid biosensor reaches over 100°/RIU. This simple structure provides a reference idea for achieving high sensitivity and tunable biosensor devices.