High-Sensitivity Terahertz Microfluidic Biosensor Based on Metal Metasurface

This paper presents a terahertz microfluidic biosensor based on metal metasurface. The resonant structure of this biosensor is four mutually symmetrical open ring structures. The analyte is placed between the metal resonant structure and the metal mirror, so that the terahertz wave interacts with the analyte fully. Simulation results show that the biosensor has an absorption rate of 99% at 0.4-0.9 THz and a sensitivity of 233GHz/RIU. In addition, the biosensor is polarization insensitive and has potential applications in nondestructive detection of trace materials and biomedicine.