Conjugation of PPV functionalized mesoporous silica nanoparticles with graphene oxide for facile and sensitive fluorescence detection of TNT in water through FRET

This paper reported a convenient method to prepare water-soluble graphene oxide (GO) functionalized by amine-modified mesoporous silica nanoparticles (MSNs) containing poly(p-phenylenevinylene) via covalent bonds. The resulted GO–PPV@MSN hybrid materials had a good dispersion and strong green fluorescence in aqueous solution. The structure, morphology and optical properties of the resulting hybrid materials were characterized. The GO-PPV@MSN can be used as a novel and effective fluorescent sensing platform for detection of 2,4,6-trinitrotoluene (TNT) in aqueous solution by fluorescence resonance energy transfer (FRET). Upon the addition of TNT, the amino groups on the surface of PPV@MSN can bind TNT molecules from solution by forming Meisenheimer complex, and this complex can absorb the green part of visible light, and strongly suppress the fluorescence emission of GO-PPV@MSN through FRET. The observed linear fluorescence intensity change allowed the quantitative detection of TNT with a detection limit down to 1.3 × 10−7 M.