▎ 摘　　要

NOVELTY - Graphene quantum dot, is claimed. The fluorescence emission peaks of the graphene quantum dots are 500-600 nm under the irradiation of the excitation light with 320-500 nm, and the fluorescence quantum yield is higher than 10%. USE - The graphene quantum dot is useful in the field of fluorescence labeling imaging, drug delivery, disease diagnosis or analytical detection (claimed). ADVANTAGE - The graphene quantum dot has high luminescent efficiency and good light stability. The method is simple and fast; has more than 35% conversion rate and large-scale production; does not need complicated and expensive apparatus. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the graphene quantum dot, comprising dissolving superoxide in graphene oxide dispersion liquid to obtain mixed reaction system, and hydrothermally reacting at 100-240 degrees C.