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

Abstract

Extremely thin layers of MoS 2 , WS 2 , and BN have come to the fore as a "beyond graphene" class of emerging 2Dmaterials 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 MoS 2 / WS 2 /BN, and also nanocarbon allotropes like graphene and C 60 , which we have previously reported as high-performance spacers in biosensing applications. The low-cost fabrication of Ag-(MoS 2 /WS 2 /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.

Plasmonics of 2D Nanomaterials: Properties and Applications

“…Moreover, controlling configuration properties such as size, contour, position, and crystalline structures is the key point to the practical applications. Thus, a new generation of efficient and accurate fabrication technique is very in need, and new methods for active material manipulating are also required to realize more functional modulations . On the one hand, latest configuration method is reported to reduce oxygen functional groups from graphene oxide into pristine graphene, by the simple and efficient method of microwave pulses instead of high‐cost CVD technique, 2D materials are closer to practical applications .…”

Chemical sensing with Au and Ag nanoparticles

“…The LSPR shift induced by local changes in the refractive index or by coupling between particles above discussed are the simplest and more immediate approaches to exploit metal nanoparticles as active materials or transducers in chemical sensing but the evanescent near field surrounding metal nanoparticles can be also exploited to strongly amplify the optical signals (including, fluorescence, IR absorption, and Raman) of molecules which are located in close proximity to the particle's surface. These techniques, called Surface-Enhanced Fluorescence (SEF), (322,323) IR absorption (SEIRA) (324) and Raman spectroscopy (SERS),( 325) have shown great potential in the field of sensing and, in particular, SERS can allow increased sensitivity up to singlemolecule detection (326,327) but their working principles and their detailed description are far beyond the scope of this review.…”

Fluorescence Based on Surface Plasmon Coupled Emission for Ultrahigh Sensitivity Immunoassay of Cardiac Troponin I

“…These challenges, however, may be resolved by surface plasmon coupled emission (SPCE) that produces the metal enhanced fluorescence due to dye–surface plasmon near field interaction. This nano-photonics technology has been explored to amplify the fluorescence signal via applying near field plasmonic technologies to the fluorescence assay without influencing analytes [ 25 , 26 ]. The excited dye molecules in close proximity to a thin metal film couples with it in a non-radiative manner, generating surface plasmons at emission wavelengths (λ em ).…”