Self-Targeting Fluorescent Carbon Dots for Diagnosis of Brain Cancer Cells

A new type of carbon dots (CD-Asp) with targeting function toward brain cancer glioma was synthesized via a straightforward pyrolysis route by using D-glucose and L-aspartic acid as starting materials. The as-prepared CD-Asp exhibits not only excellent biocompatibility and tunable full-color emission, but also significant capability of targeting C6 glioma cells without the aid of any extra targeting molecules. In vivo fluorescence images showed high-contrast biodistribution of CD-Asp 15 min after tail vein injection. A much stronger fluorescent signal was detected in the glioma site than that in normal brain, indicating their ability to freely penetrate the blood-brain barrier and precisely targeting glioma tissue. However, its counterparts, the CDs synthesized from D-glucose (CD-G), L-asparic acid (CD-A), or D-glucose and L-glutamic acid (CD-Glu) have no or low selectivity for glioma. Therefore, CD-Asp could act as a fluorescence imaging and targeting agent for noninvasive glioma diagnosis. This work highlights the potential application of CDs for constructing an intelligent nanomedicine with integration of diagnostic, targeting, and therapeutic functions.