Characterization of High Sensitivity Terahertz Metasurface Resonance With Application to Tumor Cell Detection

Terahertz (THz) metasurface produces distinctive resonance peaks that possess exceptional sensing properties for biological cells, achieving label-free, high-time resolution, and ultrasensitive detection. Thus, this study proposes a bright-bright mode electromagnetically induced transparency-like (EIT-like) THz biosensor through the fusion of resonant peaks, which is combined with an E-type and inverse C-type mode. The coupling of these two bright modes results in destructive interference of the electromagnetic field at 2.15 THz, forming an EIT window. The Fabry–Perot interference principle was employed to calculate the transmission coefficient of the resonance layer. Moreover, the optimized structure was proposed based on the circuit damping factor and resonance frequency distribution. Consequently, diverse types of tumor cells were measured in this study, the sensitivity of two resonance peak reached 434 and 548 GHz/RIU. Specifically, detection sensitivity of lung cancer-cell can reach 920 kHz/cell/mL, indicating that the EIT-like THz biosensor based on the bright-bright mode can significantly contribute to early cancer diagnosis.