The synthesis and fluorescence quenching properties of well soluble hybrid graphene material covalently functionalized with indolizine.

Chemically functionalized graphene-indolizine functionalized graphene (IMG) sheets, which can be well dispersed in different organic solvents over four months without obvious aggregation, are obtained through a 1,3-dipolar cycloaddition to graphene with pyridinium ylide. The properties of IMG sheets are investigated using a thorough set of measurements including UV-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), transmission electron microscopy (TEM), atomic force microscopy (AFM) and cyclic voltammetry (CV), and a tagging technique has exhibited the distribution of functional groups on the graphene surface. The IMG sheets show very strong quenching by a factor of ∼ 93.4% to that of indolizine, which is attributed to the fluorescence resonance energy transfer (FRET) from indolizine molecules to few-layer graphene sheets. The CV method also proved the catalytic properties of IMG sheets in some redox systems.