Highly sensitive terahertz metamaterial biosensor for bovine serum albumin (BSA) detection

Terahertz (THz) metamaterials are widely used in biosensor devices due to their unique superiority, and the demand for new high sensitivity biosensors based on THz metamaterials is increasing. This paper presents a polarization-insensitive terahertz metamaterial sensor used for BSA detection. Simulation reveals that the peak of transmission spectrum shifts obviously when the sensor is covered with analytes of different refractive index and thickness. After the sensor is covered with 10 μm thick non-destructive analytes, its sensitivity is as high as 135 GHz/RIU. Experiments show that the lowest detectable concentration of BSA solutions by this sensor is 0.1 mg/mL, the peak red shift of the transmission spectrum reaches 137 GHz when the concentration is 17.6 mg/mL, and the frequency shift percentage is 16.4%. This study provides a highly sensitive solution for biosensor detection in the pharmaceutical and food fields.