Polarization independent metamaterial-based refractive index sensor for cancer early detection

In this research, we propose a single-narrow-band metamaterial absorber to operate within the THz spectrum. The structure consists of a combination of graphene and silver located on top of a silicon dioxide layer, with silver at the bottom. The absorber achieves its highest performance at a frequency of 9.38 THz, with an absorption rate of 99.5% and a quality factor (Q) of 16.75. It should be noted that the structure is insensitive for angle variations and can tolerate incident angle changes of up to 60 °. Furthermore, the resonance frequency is influenced by the refractive index (RI) of the desired analyte, indicating that the proposed structure has the potential to be used as a highly sensitive sensor based on RI variations. Our comprehensive performance analysis shows that the sensor initially achieves a maximum sensitivity of 3.53 (THz/RIU). Additionally, the Q and figure of merit (FoM) are remarkable, making this sensor highly suitable for medical applications. Potential uses include high-resolution imaging and precise biomedical detection and sensing, such as the early and highly accurate detection of cancers.