Glucose functionalized carbon quantum dot containing organic radical for optical/MR dual-modality bioimaging

•Glucose modified carbon quantum dot containing TEMPO is prepared.•CQD-TEMPO-Glu exhibits low cytotoxicity and good biocompatibility.•CQD-TEMPO-Glu shows green fluorescence emission and high T1 relaxivities.•GLUT mediated endocytosis enhances cellular internalization of CQD-TEMPO-Glu.

The organic paramagnetic compounds nitroxides have great potential as magnetic resonance imaging (MRI) contrast agents. Herein, we report the synthesis and characterization of glucose modified carbon quantum dot containing 2,2,6,6-tetramethyl-piperidinooxy (TEMPO) for targeted bimodal MR/optical imaging of tumor cells. CQD-TEMPO-Glu shows the greatest potentials for bioimaging applications in view of low cytotoxicity, good biocompatibility, green fluorescence emission and high T1 relaxivities. The in vitro MR and optical imaging results confirm enhanced cellular internalization of CQD-TEMPO-Glu in cancer cells through GLUT mediated endocytosis. These results confirm that CQD-TEMPO-Glu is expected to be widely exploited as dual-modal contrast for cancer imaging.

Graphical abstractGlucose modified carbon quantum dot containing TEMPO (CQD-TEMPO-Glu) is expected to be exploited as targeted dual-modal contrast for cancer imaging, in view of low cytotoxicity, good biocompatibility, green fluorescence emission and high T1 relaxivities.Download high-res image (101KB)Download full-size image