THz Biomedical Sensing for Early Cancer Detection: Metamaterial Graphene Biosensors With Rotated Split-Ring Resonators

A highly sensitive graphene-based metamaterial biosensor is proposed and analyzed for early cancer detection. The sensor design employs three circular graphene split ring resonators to achieve polarization-insensitive performance. The finite element method simulation results confirm that the designed biosensor exhibits a tunable sensing capability. The material under test covers the surface of the biosensor, where resonance occurs with high absorption. The resonance frequencies of the sensor are dependent on the optical properties of the analyte sample, enabling the device to differentiate between various cancer cell types, including skin, blood, cervical, adrenal gland, and breast cancer. Graphene's tunability is leveraged to study the effects of chemical potential, relaxation time, and temperature, with the aim of maximizing the sensor's sensitivity. The designed biosensor, which detects variations in refractive index, exhibits a maximum sensitivity of 3.880 THz/RUI, a Q-factor of 8.948, and a figure-of-merit of 8.146 RUI $^{-1}$ for healthy and cancerous cell samples. The spatial patterns of electric and magnetic fields, surface current distribution, and power flow of the proposed biosensor have been thoroughly analyzed to ensure its sensitivity and suitability for biomedical applications. The results demonstrate the potential of the THz sensor for early cancer detection.