Development of a Multi-Band High-Sensitivity Polarization-Independent Absorber: A Biosensor for Simultaneous Detection of Multiple Cancer Biomarkers

Traditionally, biosensors are indeed designed to detect one specific analyte. However, recent advancements in biosensor technology have enabled the development of multiplexed biosensors capable of detecting multiple analytes simultaneously. This work proposes the detection of cervical cancer (HeLa cells), skin cancer (basal cells), and breast cancer (MDA-MB-231 cells) by analyzing the refractive index of these cells. This analysis is based on comparing the absorption spectra of healthy and cancerous cells. The proposed structure comprises three layers: a copper layer with a conductivity of 5.18 × /m, a silicon dioxide layer with a refractive index of 3.9 containing a cross-shaped hole with a depth of 3.5 µm, and a graphene layer. For the basal cell biosensor, the graphene layer is assigned a chemical potential of 0.7 eV; for the HeLa cell biosensor, it is 0.8 eV, and for the MDA-MB-231 cell biosensor, it is 0.9 eV. The absorption output extracted from CST software yields the highest sensitivity values. For basal cell detection, the highest sensitivity (7100) and a figure of merit (FOM) of 22 are achieved in mode B. For HeLa cell detection, a sensitivity of 5250 and FOM of 28 are attained in mode B. Finally, for MDA-MB-231 detection, a sensitivity of 5357 and FOM of 23 are achieved in mode B. This innovation is particularly beneficial in complex biological samples where the presence of multiple analytes may provide more comprehensive diagnostic information. The proposed multi-band high-sensitivity polarization-independent absorber serves as a notable example of this trend, demonstrating the potential for biosensors to evolve toward simultaneous detection of multianalyte targets, such as different types of cancer cells.