Nanowire‐Intensified Metal‐Enhanced Fluorescence in Hybrid Polymer‐Plasmonic Electrospun Filaments

Abstract

Hybrid polymer-plasmonic nanostructures might combine high enhancement of localized fields from metal nanoparticles with light confinement and long-range transport in subwavelength dielectric structures. Here, the complex behavior of fluorophores coupling to Au nanoparticles within polymer nanowires, which features localized metal-enhanced fluorescence (MEF) with unique characteristics compared to conventional structures, is reported. The intensification effect when the particle is placed in the organic filaments is remarkably higher with respect to thin films of comparable thickness, thus highlighting a specific, nanowire-related enhancement of MEF effects. A dependence on the confinement volume in the dielectric nanowire is also indicated, with MEF significantly increasing upon reduction of the wire diameter. These findings are rationalized by finite element simulations, predicting a position-dependent enhancement of the quantum yield of fluorophores embedded in the fibers. Calculation of the ensemble-averaged fluorescence enhancement unveils the possibility of strongly enhancing the overall emission intensity for structures with size twice the diameter of the embedded metal particles. These new, hybrid fluorescent systems with localized enhanced emission, and the general nanowire-enhanced MEF effects associated to them, are highly relevant for developing nanoscale light-emitting devices with high efficiency and intercoupled through nanofiber networks, highly sensitive optical sensors, and novel laser architectures.

Additive Manufacturing: Applications and Directions in Photonics and Optoelectronics

“…As a gentle AM process to realize 1D, 2D, and 3D photonic components with varied order, ES is enabling a novel range of nanowirebased photonic devices where light emission, scattering, amplification, and transport can all be engineered. [156,157]…”

Plasmon-Enhanced Fluorescence in Electrospun Nanofibers of Polydiacetylenes Infused with Silver Nanoparticles

“…However, to the best of our knowledge, there has been no report that explores MEF using PDA-embedded electrospun nanofibers. Nanofiber systems are of particular interest because confinement of an MEF system within nanofibers can improve the MEF over that of thin-film systems . Furthermore, when integrated into a sensor, the high specific surface area of nanofibers may improve the response time and sensitivity over those of thin films.…”

Laser Systems and Networks with Organic Nanowires and Nanofibers

“…This occurs without the need of additional fabrication steps, which could be detrimental for the emission and gain properties of the embedded, active organic compounds. In addition, the eventually subwavelength confinement in the fiber transverse dimension might lead to enhanced local electromagnetic field that can further boost emission and optical gain from incorporated emitters . The shape of NWs and NFs, combined with a refractive index ( n ) larger than the surrounding environment (air, water, etc.…”