Fig. 1. Schematic of a unit cell

Fig. 2. Absorption and reflection spectrum of the sensor

Fig. 3. The x-y plane electric field distribution of the sensor at the resonance frequency 0.66THz and 1.16 THz

Fig. 4. Absorption spectrum of the sensor under single metal structure

Fig. 5. The surface current distribution on metal microstructure and metallic reflecting layer at resonance frequency point 0.66THz and 1.16THz

Fig. 6. Equivalent circuit and equivalent complex impedance spectrum of this sensor

Fig. 7. Absorption of the proposed sensor under different incident angles for TM and TE polarizations of THz

Fig. 8. Absorption of the proposed sensor under different polarization angles for TE polarizations of THz

Fig. 9. The x-z plane electric field distributions of the sensor at resonance frequency

Fig. 10. The influence of different refractive index analytes on the sensor's sensing performance

Fig. 11. Absorption spectra of the sensor under different tangent of loss angles for the analytes

Fig. 12. The absorption and Q-factor of Mode A and Mode B with different thicknesses of the microfluidic channel

Fig. 13. The sensitivity of Mode A and Mode B with different permittivity and thicknesses of the dielectric layer