Ultra-sensitive and rotation angle-dependent plasmonic biosensors based on Ag–Ni bimetal/borophene hybrid architectures

Abstract Borophere has generated significant research interest due to its distinct in-plane anisotropy, tunable optical properties, and active surface with features required to immobilize biomolecules, which are essential in advanced biosensing applications. In this work, an ultrasensitive and highly anisotropic plasmonic sensor is proposed by vertically stacking Ag–Ni bimetal/borophene hybrid multilayers in a conventional Kretschmann configuration. Due to the advantages of the bimetal/borophene hybrid architectures, the proposed plasmonic sensor outperforms the previously reported ones in terms of angular interrogation sensitivity and dynamic controllability. Our calculations demonstrate that the angular sensitivity can be handily enhanced to over 372° RIU −1 through the incorporation of borophene nanolayers. In particular, the numerically optimized sensing structure achieves the highest sensitivity of up to 497° RIU −1 , representing a 3.28-fold increase compared to the conventional SPR configuration. Furthermore, the anisotropic nature and tunable electron densities of the borophene nanolayers enable the proposed plasmonic sensors to exhibit rotation angle-dependent behavior and electrically adjusted angular detection sensitivity. These features make the proposed sensor a promising candidate for developing intelligent plasmonic biosensing platforms for new-generation point-of-care diagnostics.