Photoplasmonic assembly of dielectric-metal, Nd₂O₃-Gold soret nanointerfaces for dequenching the luminophore emission

Abstract

A variety of materials such as low dimensional carbon substrates (1D, 2D, and 3D), nanoprisms, nanocubes, proteins, ceramics, and DNA to name a few, have been explored in surface plasmon-coupled emission (SPCE) platform. While these offer new physicochemical insights, investigations have been limited to silver as primary plasmonic material. Although, gold nanoparticles (AuNPs) exhibit robust performance, its intrinsic property to quench the emission from radiating dipoles (at distances < 5 nm) has impeded its utility. Despite the use of metal-dielectric resonances (with Au decorated SiO2 NPs) and sharp nanotips (from Au nanostars) for dequenching the emission, the enhancements obtained has been less than 200-fold in SPCE platform. To address these long-standing challenges, we demonstrate the utility of gold soret colloids (AuSCs) and photonic crystal-coupled emission (PCCE) platform. The soret nano-assemblies synthesized using adiabatic cooling technique presented integrated hotspots when taken with high refractive index Nd2O3 ‘Huygens sources’. The collective and coherent coupling between localized Mie and delocalized Bragg plasmons (of sorets), dielectric plasmons (of Nd2O3), highly confined and intense Bloch surface waves (of PCCE platform) aided in realization of dequenched, as well as amplified > 1500-fold enhancements at the photoplasmonic nanocavity interface, presenting new opportunities for multidisciplinary applications.

Cellphone-Aided Attomolar Zinc Ion Detection Using Silkworm Protein-Based Nanointerface Engineering in a Plasmon-Coupled Dequenched Emission Platform

“…In spite of exceptional plasmonic properties of AuNPs in visible and NIR optical regions with practical versatility for surface bio-functionalization, their quenching influence has remained an inevitable trade-off for utility in the SPCE platform. The “zone of inactivity” produced for fluorophores in <5 nm range from the Au surface is predominantly due to the coupling of fluorescent moieties to higher-order plasmonic modes that hasten the nonradiative pathways. − While this is the situation with bare AuNPs, recently, the so-called “quenching the quenched” phenomenon is demonstrated on account of plasmon intermixing or intercoupling in nanocavities, which eventually results in new superimposed modes that sustain improved radiative decay channels. − Consequently, the emitted photons are significantly increased at the far field from such nanogaps (near-field interfacial interaction). − Overall, this inadequacy of quenching encountered in experiments has been addressed using different approaches in the past few years and briefly listed as: (i) nanocavities generated with intense hotspots from nanogaps, (ii) metal–dielectric core–shell architectures, (iii) metal–dielectric-decorated nanointerfaces, and (iv) nanostructures with sharp tips and crevices (tip-core plasmons). − However, these methodologies present limitations of complex synthetic strategies (not-bioinspired) in nanofabrication with experimental artifacts apart from presenting moderate SPCE enhancements (<200-fold). Hence, the need for three-dimensional hotspots with heterometallic nanoassemblies has gained significant importance toward realizing dequenched and augmented SPCE enhancements.…”

Sericin-Based Bio-Inspired Nano-Engineering of Heterometallic AgAu Nanocubes for Attomolar Mefenamic Acid Sensing in the Mobile Phone-Based Surface Plasmon-Coupled Interface

“…In this context, such a comprehensive analysis aids in carefully understanding the plasmonic coupling efficiency vis-a-vis the quenching phenomena that are expected in certain nanomaterial systems. 5,8,11 All the nanointerfaces are obtained by a simple spin-coating technique. 11−17 As shown in Figure 1b, PVA and RhB were used as the polymer matrix and fluorescent dye, respectively, across all the studies to maintain the generality as well as to draw comparative conclusions of the results.…”

“…Earlier works emphasize the utility of different structural types of plasmonic nanomaterials for fluorescence-based sensing applications. 8,11,12,18 This includes nanomaterials of different shapes (rods, triangles, cubes, stars) and assembled structures (dimers, trimers, tetramers) for generation of EM hotspots with augmented field intensity. Among such explorations, nanorods have gained increased attention on account of their ability to sustain the so-called lightning rod effect.…”

Particle swarm optimization of GaAs-AlGaAS nanowire photonic crystals as two-dimensional diffraction gratings for light trapping

“…In particular, thanks to their high symmetry, are excellent platforms to design diffraction gratings able to guarantee the fine control of light coupling along certain directions for specific frequencies, depending on the design parameters The employment of optimised photonic structures to enhance specific optical functionalities is a vibrant research topic. Such a feature is largely exploited for light trapping based applications [4] such as solar cells [5,6] and sensing [7][8][9][10][11], or to control the emission of optical emitters [12][13][14]. In this context, ordered semiconductor nanowire (NW) ensembles grown onto a substrate are a suitable starting platform [15][16][17].…”