Near-infrared biosensors based on optical Tamm plasmons in one-dimensional photonic crystal heterostructre containing Weyl semimetals

• Novel Weyl semimetal biosensor works in near‑infrared range. • Tamm plasmon polaritons enable high‑performance sensing. • More Weyl layers boost figure of merit but reduce sensitivity. Weyl semimetals exhibit exceptional electronic and optical properties, positioning them as promising candidates for a wide range of applications. Notably, these materials naturally support surface waves in the infrared frequency range. In this study, we propose an optical biosensor operating in the near-infrared region, based on a combination of a one-dimensional photonic crystal and multiple layers of Weyl semimetal separated by a dielectric material. We evaluate the sensor’s performance using two diagnostic approaches: angle interrogation and wavelength interrogation techniques. Our results show that under angle interrogation, a biosensor comprising a single layer of Weyl semimetal achieves a notably high sensitivity of 160°/RIU and a figure of merit of 2486.48 RIU −1 . Alternatively, when using the wavelength interrogation method, the biosensor with a single layer of Weyl semimetal delivers superior sensing performance, reaching a maximum sensitivity of 1050 nm/RIU and a figure of merit of 1035.14 RIU −1 . These results highlight the potential of Weyl semimetal-based structures for high-performance biosensing in the near-infrared spectrum.