摘要： Nanodiamonds (NDs) have attracted much attention in biomedical research for their high chemical stability, low toxicity and good biocompatibility. However, the insufficient fluorescence of NDs largely inhibit their multi-functional bio-applications ， such as simultaneous diagnosis and chemotherapy. Herein, a multifunctional NDs-based nanoparticles(ND-TTA:RE) with excellent fluorescence and paramagnetic properties has been fabricated by covalently functionalizing NDs with rare-earth (RE=Eu3+, Gd3+) 2-Thenoyltrifluoroacetone (TTA) complexes. The NDs-based nanoparticles exhibit intense red emission and could enhance the T1-weighted MR image due to the coordinated RE ions. The in vitro/in vivo experiments demonstrate its large potential for optical and MR imaging. In addition, the ND-TTA:RE also shows good drug storage capability that reach to 375 ug/mg toward anticancer drug doxorubicin (Dox) and exhibits significant pH-dependent drug-release behavior. The MTT assays shows that the as-synthesized ND-TTA:RE have low toxicity in a concentration range from 0 to 150 mg/mL, while the Dox-loaded ND-TTA:RE (ND-TTA:RE-Dox) shows effective chemotherapy towards gastric cancer cells. The dual-mode imaging and drug delivery abilities make ND-TTA:RE a promising nanomaterial for multifunctional applications. In addition, this work may also provide a new strategy for the design of multi-functional nanoplatform.