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Updated: Aug 14, 2025

Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Diethylenetriamine-β-CD-modified carbon quantum dots for selective fluorescence sensing of Hg2+ and Fe3+ and cellular
Ju Yang1, Yunhan Yang1, Lijiao Su1
1Key Laboratory of Intelligent Supramolecular Chemistry at the University of Yunnan Province, National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials, School of Chemistry & Environment, Yunnan Minzu University, Kunming 650500, PR China.
Abstract:
Diethylenetriamine-β-cyclodextrin-modified carbon quantum dots (3 N-CQDs) were synthesized via a one-step hydrothermal method using citric acid as the carbon source and diethylenetriamine-β-cyclodextrin (3 N-β-CD) as the nitrogen source. The successful preparation of 3 N-CQDs were revealed by infrared absorption spectroscopy, ultraviolet (UV)-visible absorption spectroscopy, fluorescence spectroscopy, XRD, XPS, TEM, and TG. Further spectroscopic studies showed that the synthesized carbon quantum dots offered good anti-interference capability. The relative fluorescence quantum yield was 67.2 %. The limits of detection for Hg2+ and Fe3+ were 0.25 µM and 0.57 μM, respectively. Cytotoxicity and imaging studies showed that the prepared carbon quantum dots had low cytotoxicity, good biocompatibility, and good cellular imaging capability for HeLa cells. They offered fluorescent sensing of Hg2+ and Fe3+ in live cells. Therefore, 3 N-CQDs were ideal fluorescent probes for the detection of Hg2+ and Fe3+ in water.

