▎ 摘　　要

NOVELTY - Graphene fluorescent nanomaterial is obtained by dispersing graphene in a dispersion liquid, adding N-hydroxysuccinimide and N,N-dimethyl dodecylamine in solvent for activation of graphene, adding the activated graphene to trivalent iron salt, ethylene glycol, nitric acid and sulfuric acid, ultrasonically dispersing and reacting at high temperature, washing with water and ethanol, filtering and separating graphene material and drying. USE - The graphene fluorescent nanomaterial is used in biological imaging agent and tracer and in the field of medicine (claimed). ADVANTAGE - The graphene material obtained by the subsequent reaction has good dispersibility and good length uniformity, even after repeated reactions and the product has high purity and good fluorescent labeling effect, and has excellent biological compatibility. The preparation method is a simple and is preformed at milder condition at low cost. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of the graphene fluorescent nanomaterial comprises (S1) ultrasonically vibrating and dissolving dispersant in deionized water to obtain a dispersion liquid, where the concentration of the dispersion liquid is 1.0-2.5 mol/L, (S2) slowly adding graphene to the dispersion liquid, and ultrasonically vibrating and dissolving at frequency 1.0-2.5 KHz for 10-15 minutes, (S3) adding N-hydroxysuccinimide and N,N-dimethyl dodecylamine in a concentration ratio of 1: 1 mol to obtain 1.5-2.5 mol/L solution, adding dispersed graphene to the solution, and activating for 1-3 hours, (S4) ultrasonically dispersing the activated graphene and trivalent iron salt, ethylene glycol, nitric acid and sulfuric acid in a mass ratio of 1: (0.5-1.5): (2- 2.5): (1.2-1.5):(1.0-1.2), and carrying out ultrasonic dispersion for 10-20 minutes for first time, then reacting for 5-10 hours in the reaction kettle at 180-220℃, after reacting completely, cooling to room temperature, repeatedly washing the graphene after reaction using water and absolute ethanol, drying the graphene material obtained by separation to obtain primary graphene fluorescent nano material and (S5) repeating the steps (S2)-(S4) for 3-5 times with the initial graphene fluorescent nanomaterial obtained in step (S4) to obtain a graphene fluorescent nanomaterial.