Quad-Band Terahertz Metamaterial Sensor Based on Dual Near-Perfect Absorption for Fingerprint Identification of Cancer Cells

Early and accurate cancer diagnosis remains a critical challenge in clinical oncology due to the limitations of traditional, destructive labeling methods. To address this gap, this study proposes a novel, label-free quad-band terahertz (THz) metamaterial biosensor designed for high-precision fingerprint identification of cancer cell lines. Utilizing a classic tri-layer sandwich architecture with a top patterned geometry of dual rings, numerical simulations were systematically performed via CST Studio Suite 2024 to evaluate the sensor’s electromagnetic performance. The proposed sensor established four distinct resonance channels at 2.274, 2.349, 2.552, and 2.615 THz, achieving ultra-deep absorption profiles down to −40.36 dB. When numerically investigated against six distinct biological lineages (Basal, HeLa, Jurkat, MCF-7, MDA-MB-231, and PC-12), the sensor successfully converted minor intracellular refractive index fluctuations into highly resolved, non-overlapping spectral displacements. Performance evaluations revealed an exceptional maximum optical sensitivity of 9642.8 GHz/RIU alongside a monumental Figure of Merit (FOM) of 1928.56 RIU−1 for breast cancer cells (MCF-7), while demonstrating a peak Quality factor (Q-factor) of 870.33 for leukemia cells (Jurkat) and a high sensitivity of 6600.0 GHz/RIU for skin cancer cells (Basal). Ultimately, these decoupled multi-channel fingerprint outputs provide strong diagnostic redundancy, confirming the designed metamaterial absorber as a highly promising tool for next-generation, non-invasive early cancer diagnostic applications.