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.