Angle-insensitive microfluidic reflectarray antenna sensor for enhanced biosensing applications

Abstract This article presents a graphene-based reflectarray antenna for glucose monitoring. The reflectarray consists of three octagonal conical graphene patches placed on the top, middle, and bottom of a silicon dioxide substrate with a slit to form a microfluidic channel for sensing the biomolecules. The operating frequency of the structure changed with the change in the chemical potential of graphene. The results showed that with the chemical potential change from 0.1 to 0.6 eV, the operating frequency changed from 1.15 to 2.6 THz. The sensitivity of the antenna sensor was evaluated for different states of the structure, revealing a maximum sensitivity of 320 GHz/RIU as the refractive index varied from 1.04 to 1.26. The proposed structure demonstrated high independence from incident wave polarization and maintained consistent sensitivity for incident angles up to 60° in the TE mode.