Plasmonic luminescent core-shell nanocomposites-enhanced chemiluminescence arising from the decomposition of peroxomonosulfite

A core-shell structure of plasmonic luminescent nanocomposite, Ni@SiO2@FITC@SiO2 (NSFS) combining the stable luminescence of fluorophore with the excellent plasmonic property of metal nanomaterials, has been synthesized through layer-by-layer assembly. The effect of NSFS on the ultraweak chemiluminescence (CL) reaction of hydrogen peroxide (H2O2) and sodium bisulfite (NaHSO3) was explored for the first time. It was found that the CL intensity from the decomposition of peroxomonosulfite was significantly enhanced by NSFS. The mechanism of the nanocomposite-enhanced CL was revealed as the coupling of chemically induced excited states of fluorescein isothiocyanate (FITC) with surface plasmons of Ni nanoparticles based on studies of CL emission spectra, electron spin resonance spectra, extinction spectra and fluorescence spectra. The work sheds new light on the characteristics of the versatile materials and gives us new insight into the optical properties of fluorophores. (C) 2013 Elsevier B.V. All rights reserved.