Optimization and analysis of a high-performance multi-band terahertz metamaterial biosensor for cancer diagnostics

Early-stage cancer detection remains a critical challenge due to the limitations of conventional diagnostic methods. In this work, a highly sensitive multi-band terahertz metamaterial absorber (TMA) based on a Cu-SiO₂-Au configuration for label-free and non-invasive cancer biosensing has been proposed. The designed structure, composed of dual split-ring resonators coupled with a central cross-shaped element, exhibits four ultranarrow absorption peaks within the 1–5 THz range. Simulation results demonstrate absorption efficiencies exceeding 94 %, with sensitivities up to 857 GHz/RIU, quality factors as high as 67.4, and figures of merit (FoM) reaching 11.2 RIU⁻¹ . By exploiting refractive index variations, the TMA effectively distinguishes between normal and cancerous cells across eight cancer types, including skin, brain, cervical, blood, luminal breast, triple-negative breast, tongue, and adrenal gland cancers, with resonance frequency shifts ranging from 0.001 to 0.096 THz. Notably, the third absorption band (≈4.2–4.3 THz) exhibits consistent high performance, ensuring reliable and stable biosensing operation. The compact and miniaturized design further supports integration into portable diagnostic platforms. This study is theoretical and based on simulations with no physical prototype fabricated at this stage. But a detailed fabrication procedure compatible with conventional microfabrication techniques is provided for future experimental implementation of the proposed design. The findings in this study establish the proposed TMA as a promising candidate for next-generation terahertz biosensing technologies, enabling early cancer detection and multi-biomarker analysis in clinical applications.