A graphene quantum dot@FeO@SiO based nanoprobe for drug delivery sensing and dual-modal fluorescence and MRI imaging in cancer cells.

A novel graphene quantum dot (GQD)@FeO@SiO based nanoprobe was reported for targeted drug delivery, sensing, dual-modal imaging and therapy. Carboxyl-terminated GQD (C-GQD) was firstly conjugated with FeO@SiO and then functionalized with cancer targeting molecule folic acid (FA). DOX drug molecules were then loaded on GQD surface of FeO@SiO@GQD-FA nanoprobe via pi-pi stacking, which resulted in FeO@SiO@GQD-FA/DOX conjugates based on a FRET mechanism with GQD as donor molecules and DOX as acceptor molecules. Meanwhile, we successfully performed in vitro MRI and fluorescence imaging of living Hela cells and monitored intracellular drug release process using this FeO@SiO@GQD-FA/DOX nanoprobe. Cell viability study demonstrated the low cytotoxicity of FeO@SiO@GQD-FA nanocarrier and the enhanced therapeutic efficacy of FeO@SiO@GQD-FA/DOX nanoprobe for cancer cells. This luminomagnetic nanoprobe will be a potential platform for cancer accurate diagnosis and therapy.