A novel ratiometric fluorescence probe for the detection of copper (II) and silver(I) based on assembling dye-doped silica core-shell nanoparticles with gold nanoclusters.

Abstract

Acreatively designed and constructed a multifunctional ratiometric fluorescence probe is reportedby assembling glutathione (GSH)-protected gold nanoclusters (AuNCs) with fluorescein-doped mesoporous silica nanoparticle (FS) for the detection of Cu2+ and Ag+ ions, which could eliminate most interferences by self-calibration. Under the excitation at 450 nm, the fluorescence connected with AuNCs can rapidly respond by quenching or enhancement, respectively, for Cu2+ and Ag+ ions, while the fluorescein isothiocyante (FITC) fluorescence served as reference with negligible change. The fluorescence intensity ratio showed good linear relationships with Cu2+ and Ag+ concentrations in the range 0.5-10 μM and 0.1-8 μM, respectively. The detection limits were as low as 140 nM and 60 nM for Cu2+ and Ag+ ions, respectively. The color change induced by fluorescent intensity ratio variation could also beemployed for visual discrimination. TheAuNC-embedded FS (FS-Au) nanoprobe was successfully used for Cu2+ and Ag+ ion determination in drinking water and intracellular Cu2+ imaging, which exhibits promising prospects in cost-effective and rapid determination of both Cu2+ and Ag+ with good sensitivity and selectivity.