Tunable three-dimensional plasmonic arrays for large near-infrared fluorescence enhancement
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Metal-enhanced fluorescence (MEF), resulting from the near-field interaction of fluorophores with metallic nanostructures, has emerged as a powerful tool for dramatically improving the performance of fluorescence-based biomedical applications. Allowing for lower autofluorescence and minimal photoinduced damage, the development of multifunctional and multiplexed MEF platforms in the near-infrared (NIR) windows is particularly desirable. Here, a low-cost fabrication method based on nanosphere lithography is applied to produce tunable three-dimensional (3D) gold (Au) nanohole–disc arrays (Au-NHDAs). The arrays consist of nanoscale glass pillars atop nanoholes in a Au thin film: the top surfaces of the pillars are Au-covered (effectively nanodiscs), and small Au nanoparticles (nanodots) are located on the sidewalls of the pillars. This 3D hole–disc (and possibly nanodot) construct is critical to the properties of the device. The versatility of our approach is illustrated through the production of uniform and highly reproducible Au-NHDAs with controlled structural properties and tunable optical features in the NIR windows. Au-NHDAs allow for a very large NIR fluorescence enhancement (more than 400 times), which is attributed to the 3D plasmonic structure of the arrays that allows strong surface plasmon polariton and localized surface plasmon resonance coupling through glass nanogaps. By considering arrays with the same resonance peak and the same nanodisc separation distance, we show that the enhancement factor varies with nanodisc diameter. Using computational electromagnetic modeling, the electric field enhancement at 790 nm was calculated to provide insights into excitation enhancement, which occurs due to an increase in the intensity of the electric field. Fluorescence lifetime measurements indicate that the total fluorescence enhancement may depend on controlling excitation enhancement and therefore the array morphology. Our findings provide important insights into the mechanism of MEF from 3D plasmonic arrays and establish a low-cost versatile approach that could pave the way for novel NIR-MEF bioapplications.
Date Issued
2019-07-03
Date Acceptance
2019-06-06
Citation
ACS Applied Materials and Interfaces, 2019, 11 (26), pp.23083-23092
ISSN
1944-8244
Publisher
American Chemical Society
Start Page
23083
End Page
23092
Journal / Book Title
ACS Applied Materials and Interfaces
Volume
11
Issue
26
Copyright Statement
© 2019 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsami.9b08802.
Sponsor
British Council (UK)
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Identifier
https://pubs.acs.org/doi/10.1021/acsami.9b08802
Grant Number
216239013
EP/G060940/1
EP/K011987/1
EP/M013812/1
RP/S000798/1
EP/P02520X/1
EEZ2017450
Subjects
Science & Technology
Technology
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Science & Technology - Other Topics
Materials Science
plasmonic arrays
gold nanodiscs
near-infrared
metal-enhanced fluorescence
SPP
LSPR
nanosphere lithography
AU NANOSTRUCTURES
LIGHT-SCATTERING
METAL
NANOPARTICLE
GOLD
NANOSHELLS
SURFACE
SERIES
DOTS
DYES
LSPR
SPP
gold nanodiscs
metal-enhanced fluorescence
nanosphere lithography
near-infrared
plasmonic arrays
Biomedical Research
Fluorescence
Fluorescent Dyes
Gold
Metal Nanoparticles
Nanospheres
Nanostructures
Surface Plasmon Resonance
03 Chemical Sciences
09 Engineering
Nanoscience & Nanotechnology
Publication Status
Published
Date Publish Online
2019-06-06