Document Type

Journal Article

Department/Unit

Department of Chemistry

Language

English

Abstract

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.

Keywords

Carbon quantum dots, Lanthanide, Energy transfer, MRI, Bioimaging

Publication Date

3-2019

Source Publication Title

Colloids and Surfaces B: Biointerfaces

Volume

175

Issue

1

Start Page

272

End Page

280

DOI

10.1016/j.colsurfb.2018.11.054

Link to Publisher's Edition

https://doi.org/10.1016/j.colsurfb.2018.11.054

ISSN (print)

09277765

ISSN (electronic)

18734367

Available for download on Thursday, April 01, 2021

Included in

Chemistry Commons

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