THz Dielectric Metamaterial Sensor With High Q for Biosensing Applications

This research exhibits the design and analysis of high-quality factor ( ${Q}{)}$ dielectric metamaterial sensor (DMMS) for biosensing applications. The proposed sensor consists of a silicon-based dielectric resonator along with a graphene ring, silicon dioxide (SiO $_{{2}}{)}$ substrate, and gold metallic layer at the bottom. A silicon-based square ring resonator (SSRR) with $\varepsilon _{\text {sr}} =11.9$ is positioned at the top of the SiO2 layer. A graphene-based circular-shaped ring (GCR) has a thickness of 0.34 nm with an inner radius of $\text {g}_{\text {ri}}=8\,\,\mu \text{m}$ and an outer radius of $\text {g}_{\text {ro}}$ = 10 $\mu \text{m}$ is placed on the top of the SiO2 layer. The sensor provides perfect absorption at a frequency of 4.06 THz with an absorption rate of 99.993 %. The absorber performance is also verified by the circuit model using the transmission line method. Tunability and controllability are obtained for the proposed absorber by changing the chemical potential of graphene. The proposed structure exhibits a maximum sensitivity of 2.2 THz/TU with a high ${Q}$ of 927.5. Furthermore, the absorber’s performance remains stable over the incidence angle up to 80°, providing an absorptivity greater than 85%. Moreover, the proposed sensor is insensitive to polarization. The unique features of the proposed absorber are its ultra-thin structure, simple design, tunability, polarization insensitivity, ultra-narrow absorption bandwidth (BW), high sensitivity, high figure of merit (FOM), and very high quality factor ( ${Q}{)}$ , making it suitable for detection of dengue, malaria, and glucose.