▎ 摘　　要

The recent development of nanoprobes with multiple biomolecular detection functionalities have attracted considerable interests in various biomedical imaging applications. Herein, we have designed and prepared Fe3O4@chitosan-graphene quantum dots (Fe3O4@CS-GQDs) nanocomposites for fluorescence and magnetic resonance imaging (MRI). The photoluminescent spectra of Fe3O4@CS-GQDs nanocomposites exhibit an emission peak at 434 nm under the ultraviolet excitation light of 330 nm. Fe3O4@CS-GQD nanocomposites show the excellent MRI results in aqueous solution. The cytotoxicity of Fe3O4@CS-GQDs nanocomposites is observed low cytotoxicity in Hela cells. Based on the results, Fe3O4@CS-GQDs nanocomposites are confirmed as promising fluorescence and MRI imaging contrast agents for tumor detection.