Chemiluminescence reaction of glucose-derived graphene quantum dots with hypochlorite, and its application to the determination of free chlorine

Graphene quantum dots (GQDs) were prepared by a new and facile procedure, and their chemiluminescence (CL) reaction with hypochlorite was studied. It was found that hypochlorite can directly oxidize GQDs to give rise to CL emission, and that the surfactant cetyl trimethyl ammonium bromide enhances CL by a factor of about 18. CL and fluorescence spectra were acquired, and the effect of radical scavengers on the reaction was studied. This CL system was used to develop a simple and sensitive method for the determination of hypochlorite in the 0.5 mu M to 1.0 mM concentration range, with a detection limit of 0.3 mu M. The method was successfully applied to the determination of free chlorine in (spiked) samples of tap water and pool water.