In this work, a novel electrochemiluminescence (ECL) sensor has been developed to detect miRNA-210 in the serum of triple negative breast cancer (TNBC) patients. The luminous MoS2 nanosheets were synthesized via the solvothermal method and served as ECL emitters for the first time. As a result, the ECL properties of as-prepared MoS2 nanosheets were significantly improved. Furthermore, the biomimetic magnetic vesicles were used as capture platform in the ECL sensing strategy. Due to the highly efficient fluidity and magnetic property, the biomimetic vesicles with hairpin aptamers can capture target gene in the serum. After magnetic separation, the captured miRNA-210 can trigger the target-catalyzed hairpin assembly (CHA) sensing process on the magnetic electrode and hybridize MoS2 nanosheets labeled probe DNA. The concentration of miRNA-210 can be quantified by the ECL enhancement of the MoS2 nanosheets. This approach has achieved the sensitive detection for miRNA-210 in a range from 1 fM to 100 pM with the detection limit of 0.3 fM. The luminous MoS2 nanosheets-based ECL sensing system with the biomimetic vesicles would provide a new pathway to explore 2D nanomaterials for developing a wide range of bioanalytical applications.