Plasmon-Enhanced Ultrasensitive Surface Analysis Using Ag Nanoantenna.

Authors :: Li CY
Gao JH
Yi J
Zhang XG
Cao XD
Meng M
Wang C
Huang YP
Zhang SJ
Wu DY
Wu CL
Xu JH
Tian ZQ
Li JF
Source :: Analytical chemistry [Anal Chem] 2018 Feb 06; Vol. 90 (3), pp. 2018-2022. Date of Electronic Publication: 2018 Jan 10.
Publication Year :: 2018
Abstract: Raman scattering and fluorescence spectroscopy permeate analytic science and are featured in the plasmon-enhanced spectroscopy (PES) family. However, the modest enhancement of plasmon-enhanced fluorescence (PEF) significantly limits the sensitivity in surface analysis and material characterization. Herein, we report a Ag nanoantenna platform, which simultaneously fulfills very strong emission (an optimum average enhancement of 10 <superscript>5</superscript> -fold) and an ultrafast emission rate (∼280-fold) in PES. For applications in surface science, this platform has been examined with a diverse array of fluorophores. Meanwhile, we utilized a finite-element method (FEM) and time-dependent density functional theory (TD-DFT) to comprehensively investigate the mechanism of largely enhanced radiative decay. PES with a shell-isolated Ag nanoantenna will open a wealth of advanced scenarios for ultrasensitive surface analysis.