8-Hydroxyquinoline functionalized ZnS nanoparticles capped with amine groups: A fluorescent nanosensor for the facile and sensitive detection of TNT through fluorescence resonance energy transfer

8-Hydroxyquinolines (HQs) functionalized ZnS nanoparticles (NPs) with an amine-capping layer (ZnS-NH2-Q NPs) were prepared by a ligand-exchange process. FT-IR, XRD, NMR, TEM and fluorescence spectrometer were used to characterize the novel ZnS-NH2-Q NPs. Upon the addition of 2,4,6-trinitrotoluene (TNT), the amino groups on the surface of ZnS-NH2-Q NPs can bind TNT molecule from solution by forming Meisenheimer complex. This complex absorbs the green part of visible light, and strongly suppresses the fluorescence emission of the ZnS-NH2-Q NPs through Fluorescence Resonance Energy Transfer (FRET). The observed linear fluorescence intensity response for TNT in the range of 0-1.89 mu M allows the quantitative detection TNT, with a detection limit down to 10 nM. (C) 2012 Elsevier Ltd. All rights reserved.