Chemiluminescence of graphene quantum dots and its application to the determination of uric acid

We report on the chemiluminescence (CL) of graphene quantum dots (GQDs) induced by direct chemical oxidation. GQDs were prepared by a simple carbonization method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and Raman spectroscopy. It was found that Ce(IV) could oxidize GQDs to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra. It was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. In order to show the analytical application potential of GQDs-Ce(IV) CL system, it was applied to the determination of uric acid. Under the optimized conditions, the proposed CL system exhibited excellent analytical performance for determination of uric acid in the range of 1.0 x 10(-6) M-5.0 x 10(-4) M with a limit of detection of 5.0 x 10(-7) M. The method was applied to the determination of uric acid in human plasma and urine samples, with satisfactory results. (C) 2014 Elsevier B.V. All rights reserved.