High Performance of Terahertz Sensor Based on Double-Split Hexagonal Ring Metamaterial

Terahertz (THz) has significant potential applications in biosensing, but its detection sensitivity still needs to be improved. Metamaterials (MMs) can effectively improve THz sensing sensitivity due to their field-enhancing properties. In this work, we designed and fabricated a double-open hexagonal ring MM with a high refractive index sensitivity of 430 GHz/RIU. The resonant properties of MMs were demonstrated by both simulations and experiments. The sensing performance was tested with different concentrations of glucose and bovine serum protein (BSA) solutions. The results showed that the sensitivity of the MM to glucose and BSA solution reached 0.37 GHz/(mg/dL) and 36.44 GHz/(mg/mL), respectively, while the detection limits of glucose and BSA solution reached 9.867 mg/dL and 0.16 mg/mL, respectively. The proposed MM sensor has potential application scenarios in the THz biomedical field.