▎ 摘　　要

NOVELTY - Synthesizing graphene carbon quantum dot comprises (i) adding fullerene (60C) and sodium hydroxide into a agate mortar, grinding and mixing uniformly; (ii) placing the fine reaction products into a clean crucible and calcining in a muffle furnace; (iii) taking out the solid, after finishing the reaction, cooling to room temperature, dissolving the solid in ultra pure water, centrifuging and taking supernatant; (iv) placing the supernatant in a dialysis bag and dialyzing until pH of water is neutral; and (v) freeze drying the dialysis solution to obtain brown-yellow powder. USE - The quantum dot is useful for detecting intracellular iron concentration, and quenching fluorescence iron ions (all claimed). ADVANTAGE - The quantum dot has good biocompatibility (claimed). The method is simple and does not require subsequent modification steps. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for the graphene carbon quantum dot prepared by the above method, where the graphene carbon quantum dots are homogeneous monodispersed spheres of particle size 2-3 nm and crystal grid distance of 0.24 nm, and the quantum dot has height of 2.5 plus minus 1.5 nm, is provided with carboxy and hydroxy containing surface, has maximum excitation wavelength of 290 nm, has maximum emission wavelength of 400 nm, has quantum yield of 4.8%, and the emission wavelength with excitation wavelength is red shift to red shift.