MoS2 surface plasmon resonance based high-resolution THz biosensor using a dual D-shaped channel micro-structured fiber

Currently, the field of THz bio-detection faces challenges in terms of sensitivity, efficiency and anti-interference, to which high-sensitivity, multi-channel optical fiber sensors offer a key solution. Here, a high-resolution THz biosensor based on surface plasmon resonance (SPR) is achieved by depositing a MoS2 2 excitation layer on a dual- channel micro-structured fiber (MSF). The dual D-shaped channels are completely separated by support-arm claddings to ensure the detection independence, and the dual-channel introduces self-referencing to reduce the measurement bias caused by environmental changes. Transmission performance of the SPR-MSF sensor is optimized by adjusting its structural design parameters based on a finite element method (FEM). The results show that the proposed SPR-MSF biosensor presents high amplitude sensitivity of up to 384.80 RIU-1 and high wavelength sensitivity of 223.45 mu m/RIU, corresponding to sensing resolution of 4.47 x 10(-7) RIU. Furthermore, the dual-channel wavelength sensitivity and sensing resolution can be improved to 602.52 mu m/RIU and 1.66 x 10(-7) RIU, respectively, with a ZnO thin film deposited in the detection channel. With its unique high sensitivity and high resolution, as well as other advantages provided by fiber-based such as the compactness and biocompatibility, the proposed SPR-MSF bio-sensor has potential applications in biochemical sensing, biomolecule identification, non-invasive cell analysis and many other THz detection fields.