▎ 摘　　要

NOVELTY - Fluorescent probe comprises (a) graphene oxide microparticle crystal having average values of 1-5, and (b) targeting ligand bound to the graphene oxide microparticle through covalent bond, where diameter of the compound (a) and (b) are in a aspect ratio (b)/(a) having average value of 1-5. USE - The fluorescent probe is useful for performing bioimaging (claimed). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for preparing the above-mentioned fluorescent probe, which involves obtaining the graphene oxide microparticles as raw material, sintering the raw material at 300 degrees C or more, obtaining graphene oxide microparticles having crystallinity, and binding the targeting ligand to the graphene oxide microparticle through covalent bond.