All-Metal Nested Square Rings THz Metamaterial for Sensitive Biosensor in the Detection of Glucose

This article presents an all-metal THz metamaterial biosensor, which adopts two nested square rings interconnected by metal bars as a unit cell. The metamaterial is fabricated on a copper foil using laser micro-machining. The copper foil is periodically patterned with a continuous array of nested rings. The simulation results show that the refractive index sensitivity of the metamaterial sensor is 210 GHz/RIU. To evaluate its sensing capabilities, glucose solution is selected as the detection substance. The experimental results demonstrate that the sensor's minimum detection concentration is 0.05 mol/L. The metamaterial biosensor exhibits simple structure, high repeatability, and easy fabrication, rendering it a promising candidate for biological detection and disease diagnosis applications.