Highly Sensitive Triple-Band Terahertz Metasensor for Multi-Disease Detection

Terahertz (THz) metasurface absorbers (MSAs) have emerged as highly promising devices for biomedical sensing due to their strong near-field confinement and high-quality resonances. In this article, a triple-band hybrid MSA consisting of square ring, circular ring, and modified Jerusalem cross resonators for multi-disease detection with high angular stability (up to 70°) is presented. The proposed design achieved near-perfect absorption (>99%) at 1.37, 3.06, and 3.91THz, with quality factors (QFs) of 23.87, 55.13, and 37.94, respectively. The metasensor provides high sensitivity up to 2.4THz/refractive index unit (RIU) and a figure of merit (FOM) of 61.53, covering a wide refractive index range (1.35–1.5). Owing to the triple-band operation, strong field confinement, and angular stability, the design enables precise detection of multiple biological analytes, including cancer biomarkers, hemoglobin variations, and tumor markers, providing a compact and robust platform for advanced, label-free THz biosensing applications. The integration of three dissimilar resonators within a single compact metasurface enables independent resonance control and multifrequency biosensing using a single device.