Synthesis of graphene oxide/rare-earth complex hybrid luminescent materials via π-π stacking and their pH-dependent luminescence

2-Thenoyltrifluoroacetone (Tta) and 1,10-Phenanthroline hydrate (Phen) were used as ligands for Eu3+ ions to prepare graphene oxide (GO)/rare-earth (RE) complex hybrid luminescent materials by a new method. The as-prepared products are characterized via fluorescence microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV-Vis absorption spectroscopy, X-ray diffraction, fluorescence spectroscopy, and thermogravimetric analysis. The hybrid materials exhibit good solubility, long luminescent lifetime, high fluorescence quantum yield, good thermal and photo stability. Moreover, their fluorescence properties in sodium acetate/acetic acid buffer solution over the pH range from 3.6 to 5.4 are also studied. These properties of hybrid materials provide an important basis for their application in medicine, as potential biological markers, and as drug delivery vehicles.