Plasmon-Induced Transparency-Based Metamaterial Sensor for Highly Sensitive Glucose Detection

In this work, we propose a metamaterial based on plasmon-induced transparency for the detection of glucose solutions. The unit cell structure of this metamaterial comprises of two rectangular strips and a pair of "arch-bridge" shaped structures fabricated on a silicon dioxide surface. Simulation results indicate that the biosensor exhibits two resonance frequencies at 1.71 and 2.30 THz, respectively, with a sensitivity of 471.43 GHz/RIU (refractive index unit) at the higher frequency resonance. The sensor fabrication is accomplished through photolithography and its performance is validated with a commercial terahertz time-domain spectrometer. Glucose solutions of five different concentrations are prepared for testing. Experimental results demonstrate that at the higher frequency resonance, the sensor exhibits a sensitivity of 6.63 GHz/(mmol/L) and a limit of detection of 0.0890 mmol/L. This indicates the sensor’s high sensitivity to glucose solutions. Hence, this study presents a potential alternative for glucose detection, with implications for early diabetes monitoring.