▎ 摘　　要

NOVELTY - Preparing graphene-rare earth up-conversion composite nano-microsphere comprises preparing histidine-functionalized graphene quantum dot, preparing graphene quantum dot-rare earth fluoride up-conversion complex, loading drug and compounding with photothermal agent gold nanoparticles to obtain graphene-rare earth up-conversion composite nanospheres. USE - The graphene-rare earth up-conversion composite nanospheres is useful in imaging, and for controlled release of drugs in vivo (all claimed). ADVANTAGE - The method: utilizes strong coordination ability of histidine and rare earth ions to realize regulation of size and morphology of rare earth UCNP; utilizes nanographene's strong ability to absorb infrared light and efficient energy transfer with rare earth UCNP, which improves upconversion luminous efficacy of rare earth UCNP materials; utilizes nano-gold that absorbs visible light in up-conversion luminescence to generate heat, and realizes light controlled release of drug. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for use of graphene-rare earth up-conversion composite nanospheres in imaging, and for applying to controlled release of drugs in vivo.