MoS₂/WS₂/BN-Silver Thin-Film Hybrid Architectures Displaying Enhanced Fluorescence via Surface Plasmon Coupled Emission for Sensing Applications

Extremely thin layers of MoS₂, WS₂, and BN have come to the fore as a “beyond graphene” class of emerging 2D-materials that display many interesting properties and have wide technological applications. In this study, we report the first time engineering of these novel nano 2D-materials as efficient spacer layer components in silver (Ag) based thin-film stacks that generated up to 17-fold enhancement in the emission intensity of rhodamine B (RhB) fluorophore molecules; based on the surface plasmon coupled emission (SPCE) platform. The exceptional mechanical, thermal, and chemical stability of these 2D-spacer layers enabled effective surface passivation of Ag thin-films. The superior signal enhancements observed from the different 2D-spacer substrates may be attributed to optimal changes in radiative decay rates of excited RhB states. In a manner not reported before, we demonstrate the tunability of SPCE signal enhancements, on choosing spacer materials of appropriate refractive index. In this work, we further present a detailed comparison between MoS₂/WS₂/BN, and also nanocarbon allotropes like graphene and C₆₀, which we have previously reported as high-performance spacers in biosensing applications. The low-cost fabrication of Ag-(MoS₂/WS₂/BN) thin-film architectures, synergistically coupled with superior fluorescence signals produced by SPCE, promises the application of these portable platforms for the detection of various biochemical analytes with very high levels of sensitivity