Fig. 1. Structural diagram and terahertz transmission spectrum of terahertz metamaterial biosensor with double split-ring structure. (a) Structural diagram; (b) terahertz transmission spectrum

Fig. 2. Electric field diagram, surface current diagram and LC resonance model diagram of terahertz metamaterial biosensor with double split-ring structure at 0.776 THz. (a) Electric field diagram; (b) surface current diagram; (c) LC resonance model diagram

Fig. 3. Influence of periodic size variation of cell structure on transmission spectrum and resonant dip frequency of biosensor. (a)(b) P_x; (c)(d) P_y

Fig. 4. Influence of structural parameters of split-ring on transmission spectrum and resonant dip frequency of biosensor. (a)(b) g;(c)(d) l; (e)(f) s; (g)(h) w

Fig. 5. Influence of incident angle θ_i and polarization angle θ_p on transmission spectrum. (a) Angle direction definition during CST simulation; (b) influence of incident angle variation on resonance frequency and transmissivity; (c) influence of polarization angle variation on resonance frequency and transmissivity

Fig. 6. Influence of refractive index variation of analyte on resonance frequency of biosensor. (a) Structural diagram of biosensor;(b) transmission spectrum varying with refractive index; (c) fitting curve of refractive index sensitivity

Fig. 7. Influence of refractive index variation of analyte on resonance frequency of biosensor with substrate of silicon. (a) Transmission spectrum varying with refractive index; (b) fitting curve of refractive index sensitivity

Fig. 8. Influence of refractive index variation of analyte on resonance frequency of biosensor with single split-ring structure.(a) Transmission spectrum varying with refractive index; (b) fitting curve of refractive index sensitivity

Fig. 9. Micrograph of terahertz metamaterial biosensor with double split-ring structure

Fig. 10. Schematic diagram of continuous wave terahertz spectrum system

Fig. 11. Transmission spectra and Hill fitting results of biosensor under different BSA solutions. (a) Transmission spectrum; (b) Hill fitting curve

Fig. 12. Transmissivity variation diagram of biosensor under BSA with different mass concentrations