A Compact Metamaterial Biosensor for Multi-Virus Detection With Tunability and High Incidence Angle Absorption

In this research, we introduce a metamaterial biosensor designed for the detection of various viruses. The proposed sensor configuration comprises four square split ring resonators (SRR) coupled with a central graphene ring. The strong coupling between SRR and graphene ring results in near-perfect absorption at a frequency of 1.354 THz. To enhance versatility, the sensor's performance can be tuned and controlled by adjusting the chemical potential ( \mu _{\mathrm {c}} ) of the graphene. Additionally, we validate the sensor's functionality through an equivalent circuit model. Moreover, the proposed sensor demonstrates outstanding performance metrics, including a high sensitivity (S) of 1.7 THz/RIU, a Figure of Merit (FOM) of 165.09 RIU−1, high-quality factor (Q) of 112.5. Despite its reduced structural thickness of 3~\mu \text{m} , it remains suitable for integration into nanotechnology devices. Furthermore, the absorber exhibits exceptional absorption properties even at steep incidence angles, expanding its applicability in diverse scenarios. Its potential to detect a wide range of viruses, including malaria, dengue, herpes simplex virus, influenza, and HIV, and distinguish various cancerous cells, holds promise for advancing biosensing applications.