Mitochondria-targetable carbon quantum dots for differentiating cancerous cells from normal cells

In this study, a series of fluorescent carbon quantum dots (or carbon dots, CDs) with inherent mitochondrial targeting/imaging and cancerous/normal cell differentiation capabilities were prepared by a one-pot solvothermal treatment of glycerol and a silane molecule. Glycerol acted as a solvent and carbon source, and the silane molecule acted as a passivation agent. The as-prepared CDs could specifically and stably (for at least 24 h) visualize mitochondria of various types of cells without the introduction of mitochondria-targeting ligands (such as triphenylphosphonium). In addition, the CDs exhibited extraordinary features including facile synthesis, good water solubility, favorable biocompatibility, and excellent photostability as compared to commercial mitochondrial probes. Moreover, the CDs could efficiently distinguish cancerous cells from normal cells with high fluorescence contrast due to differences in their mitochondrial membrane potentials and substance uptake efficiencies. More importantly, to the best of our knowledge, the present study provides the first example of using CDs to distinguish cancerous cells from normal cells. The remarkable features of mitochondria-targeted imaging and cancerous cell recognition make the CDs an excellent fluorescent probe for various biomedical applications.