Fractal Carbon Islands on Plastic Substrates for Enhancement in Directional and Beaming Fluorescence Emission

Abstract

In the past decade, the exploration for frugal nanomaterials that manipulate the electromagnetic field for the development of next-generation plasmonic technologies has been on the rise. Fractal nanoparticles with augmented electromagnetic field enhancements have their utility in broad-band optics and electrochemical applications. Here we present a simple, ultrafast method to deposit fractal carbon islands from candle soot on plastic substrates. Fractal carbon islands, generated here, have been utilized in spacer and cavity architectures that provide an 80-fold enhancement in directional and beaming emissions from radiating dipoles coupled to surface plasmon polaritons.

Silver Soret Nanoparticles for Femtomolar Sensing of Glutathione in a Surface Plasmon-Coupled Emission Platform

“…Currently, the rapid progress in multifarious nanofabrication techniques has made the study of the spacer layer more insightful (with different physicochemical outcomes) in the broad area of plasmonics . Spacer-layer engineering has gained tremendous interest in the pure nanophotonics field such as EM cloaking using a silicon nanospacer, directional and beaming emissions in the SPCE from candle-soot-based fractal islands, and on and off resonances from graphene spacer thickness-dependent plasmon tunneling, to name a few. Additionally, researchers have also utilized spacer layers in applications pertaining to the plasmon-enhanced solar membrane distillation of seawater and smartphone-based surface-enhanced fluorescence for point-of-care diagnostics in resource-limited settings .…”

“…Earlier investigations suggested that potential MDM (metal–dielectric–metal) substrates, having two continuous metal thin films, can steer the fluorescence into a narrow beam and allow better control over the emission directionality. ,, This is exceedingly desirable for improved fluorescence detection in many applications. , In the current work, we present a configuration that consists of a dielectric layer sandwiched between an assembly of metallic NPs (Ag-SCs) and a metal thin film, hence, the term “pseudo-MDM”. It is worth mentioning that this is for the first time that Ag-SCs are adopted in the SPCE framework and have been studied in the “extended cavity architecture”, which is hypothesized as a “pseudo-metal–dielectric–metal” architecture.…”

Engineering of Exciton–Plasmon Coupling Using 2D-WS2 Nanosheets for 1000-Fold Fluorescence Enhancement in Surface Plasmon-Coupled Emission Platforms

“…A 30 nm layer of PVA having a uniform dispersion of the nanomaterial with the same loading as in the dispersion used for spin coating was used for further studies. The parameters used to spin-coat PVA for obtaining the cavity layer have been extensively studied before to obtain a reproducible 30 nm thick film. , This fabrication process having both the dye and the plasmonic material in a single layer, when spin-coated on the conventional SPCE substrate, has been termed as the cavity architecture. , Similarly, using 5, 10, 15, and 20 mg mL –1 of 1T–WS 2 , the SPCE substrate was fabricated. For studying the effect of thermal treatment, the SPCE substrate with different concentrations (1–20 mg mL –1 ) of 1T–WS 2 was fabricated and heated at 190 °C for 5 min.…”

“…2,24 This fabrication process having both the dye and the plasmonic material in a single layer, when spin-coated on the conventional SPCE substrate, has been termed as the cavity architecture. 11,12 Similarly, using 5, 10, 15, and 20 mg mL −1 of 1T−WS 2 , the SPCE substrate was fabricated. For studying the effect of thermal treatment, the SPCE substrate with different concentrations (1−20 mg mL −1 ) of 1T−WS 2 was fabricated and heated at 190 °C for 5 min.…”

“…In the cavity architecture, the radiating dipole is sandwiched in the infinitesimal gap between the metal thin film and the plasmonic nanomaterial. So far, numerous studies have presented augmentation of fluorescence emission with the use of different materials such as fractal carbon islands, 12 graphene oxide and silver-decorated graphene oxide, 13 Aglignin nanocomposites, 14 low-dimensional carbon materials, 15 and DNA architectures. 16 In addition to these materials, graphene and graphene-oxide-based two-dimensional (2D) plasmonic nanomaterials have also been explored for SPCE applications.…”