Enhanced Long-Range Surface Plasmon Effect Based on Zr₂CO₂ MXene and MoSe₂ Heterostructures for SPR Biosensors With High FOM

MXenes-based van der Waals heterojunction materials with excellent chemical stability and bioaffinity have been widely used in biosensing in recent years. We propose a new MoSe2@Zr2CO2 heterostructure as a long-range surface plasmon resonance (LRSPR) sensor based on the Kretschmann configuration from simulation and optimize the structure parameters algorithmically. First, we investigate the effect of different layers of MoSe2@Zr2CO2 heterojunction on the LRSPR wave. The results show that the optimal number of layers for heterogeneous layers is 18. Second, the effects of dielectric thickness and refractive index (RI) on sensitivity are investigated in depth, and optimized structural parameters are obtained. Finally, the effect of prisms with different refractive coefficients on the sensor performance is also discussed, and it is shown that prisms with lower refractive coefficients can effectively improve the sensitivity performance of the sensor. The sensor response performance to biomolecules is greatly enhanced due to the gain of light absorption and SPR. Compared with the conventional precious metal Au-based (50 nm) thin-film SPR sensor, the figure of merit (FOM) of the sensor is improved by a factor of 8.16, and higher sensitivity (92.48°/RIU) and quality factor (QF) (319.63 RIU−1) are obtained in the visible range.