A terahertz metamaterial biosensor based on spoof surface plasmon polaritons transmission line for avian influenza virus detection

Abstract

A highly sensitive terahertz biosensor based on spoof surface plasmon polaritons for avian influenza virus detection is presented in this paper. The sensor utilizes a grating structure to support spoof plasmon modes with high-quality factors, enabling detection at 1.93 THz with a Q-factor of 690. The slow-wave transmission lines (SWTL) are connected to a metamaterial unit cell to achieve strong field confinement and resonance at terahertz frequencies. Various types of the H1N1, H5N2, and H9N2 are considered as material under test which is placed over the sensor. The main elements for controlling the resonance and increasing the Q-factor are the width of the gap and the unit-cell and the parametric studies show that the selected dimensions are optimum for this sensor. The high sensitivity is attributed to the excitation of spoof plasmons that concentrate the terahertz field within micro-scale regions, interacting with minute amounts of analyte. The full-wave method of the finite integrated technique (FIT) as a high-accuracy time domain method is used for the simulation of the proposed structure and it is compared with the finite element method (FEM) for confirming the results. Moreover, the transmission line model (TL) and circuit model (results) are extracted which prove the truth of the full-wave results. The average sensitivity (Savg) of this sensor for material in the range of 1.1 to 1.5 is obtained up to 8 %. This work demonstrates the application of plasmonic metamaterials to terahertz biosensing for virus detection with high sensitivity.