Octa- square split ring-shaped supercell-based plasmonic metamaterials for enhanced dual-spectral detection of cancer biomarkers.

Cancer remains one of the leading causes of mortality worldwide, making early detection crucial for improving treatment outcomes. Plasmonic biosensors offer a promising non-invasive approach to detecting cancer cells in their early stages. In this study, we investigate an LSPR-based biosensor employing an innovative plasmonic metamaterial composed of an eight-ring supercell array for cancer detection. The proposed structure features eight ring-shaped cubic supercells, interconnected via a soft-cell interface. Analysis focused on three widely used metals in plasmonics: aluminium, silver, and gold. The evaluation was conducted using the three-dimensional finite difference time domain (FDTD) method. Leveraging the localized surface plasmon resonance (LSPR) effects of the gold nanostructure, dual resonance peaks are achieved in the inductive-capacitive (LC) mode. The designed sensor operates effectively in the near-infrared region, covering the wavelength range of 1000-2100 nm. Sensitivity and figure of merit (FOM) for the first mode are measured at 604 (nm/RIU) and 14.72 (RIU-1), respectively, while for the second mode they reach 1097.1 (nm/RIU) and 15.64 (RIU-1). This biosensor demonstrates potential for distinguishing between various cancer types, including skin, cervical, blood, adrenal gland, and breast cancers, by detecting refractive index differences between healthy and cancerous cells.