▎ 摘　　要

NOVELTY - Up-conversion nanoparticles are re-dispersed in water, amino-terminated hyperbranched polymer solution is added, ultrasonically treated, centrifuged, and washed with distilled water and ethanol to obtain amino-terminated hyperbranched polymer modified up-conversion nanoparticles. Amino-terminated hyperbranched polymer modified up-conversion nanoparticles are re-dispersed in water, graphene oxide is added, ultrasonically treated, centrifuged, washed with distilled water and ethanol, and dried, to obtain up-conversion nanoparticles-graphene oxide composite material. USE - Preparation of up-conversion nanoparticles-graphene oxide composite material used in photothermal therapy, photodynamic therapy, fluorescence labeling and biological probes. ADVANTAGE - The method enables simple preparation of up-conversion nanoparticles-graphene oxide composite material having excellent water solubility. DETAILED DESCRIPTION - 1 mmol Rare earth trifluoroacetate of formula: Ln(CF3COO)3, where Ln is Y, Yb, Tm or Er, 10 mmol sodium fluoride and 20 ml organic solvent are added to 50 mL three-neck flask, heated at 120 degrees C for 1 hour, magnetically stirred at 320 degrees C for 1 hour, naturally cooled to room temperature, absolute ethanol is added, precipitated by centrifugation, and washed with water and ethanol, to obtain up-conversion nanoparticles. Up-conversion nanoparticles are re-dispersed in water, in ratio of 1:1-1:10, 0.01-100 g/L amino-terminated hyperbranched polymer solution is added, ultrasonically treated for 10-120 minutes, centrifuged, and washed with distilled water and ethanol to obtain amino-terminated hyperbranched polymer modified up-conversion nanoparticles. Amino-terminated hyperbranched polymer modified up-conversion nanoparticles are re-dispersed in water, predetermined amount of graphene oxide is added, ultrasonically treated at 80 degrees C for 1-12 hours, centrifuged, washed with distilled water and ethanol, and dried, to obtain up-conversion nanoparticles-graphene oxide composite material. The organic solvent is oleic acid and/or carbon octadecene.