Department of Chemistry
The carbon quantum dots termined with amine groups (CQDs-NH2) were synthesized in one-pot hydrothermal method with citric acid as carbon source and branched polyethylenimine (BPEI) as passive agent, which was then covalently linked to 1, 4, 7, 10-tetraazacyclononane (DOTA) framework to yield CQDs-DOTA. The CQDs-DOTA provide excellent ligand scaffolds for the chelation of lanthanide ions, yielding the related complexes CQDs-DOTA-Ln (Ln = Eu, Tb, Yb and Gd). The successful preparation of CQDs-DOTA-Ln was validated by TEM, XRD, XPS, and FT-IR spectroscopy. The CQDs-DOTA-Ln (Ln = Eu, Tb and Yb) exhibited the characteristic emissions of related lanthanide ions, indicating the CQDs could sensitize the luminescence of lanthanide ions. Besides, the CQDs-DOTA-Gd could serve as an excellent T1-weighted MR imaging probe due to the chelation of paramagnetic Gd (III) ions and good hydrophilicity. The cytotoxicity of CQDs-DOTA-Ln was evaluated through MTT assay upon HeLa cells. The images from fluorescence microscopy further verified their applications in bioimaging in vitro. Due to the good biocompatibility, low toxicity, and high contrast efficiency, the CQDs-DOTA-Ln with Vis/NIR fluorescence and MR multi-modal imaging performance could be used as potential contrast agents for clinic applications.
Carbon quantum dots, Lanthanide, Energy transfer, MRI, Bioimaging
Source Publication Title
Colloids and Surfaces B: Biointerfaces
Link to Publisher's Edition
Wu, F., Yue, L., Yang, L., Wang, K., Liu, G., Luo, X., & Zhu, X. (2019). Ln(III) chelates-functionalized carbon quantum dots: Synthesis, optical studies and multimodal bioimaging applications. Colloids and Surfaces B: Biointerfaces, 175 (1), 272-280. https://doi.org/10.1016/j.colsurfb.2018.11.054
Available for download on Thursday, April 01, 2021