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Enhanced fluorescence of Zn-doped carbon quantum dots using zinc citrate chelate as precursor for fluorescent sensor applications.
- Source :
-
Materials Science & Engineering: B . Feb2021, Vol. 264, pN.PAG-N.PAG. 1p. - Publication Year :
- 2021
-
Abstract
- • The Zn-CQDs are synthesized based on zinc citrate chelate as the precursor is proposed. • Zn-CQDs obtain a high photoluminescence intensity, which is eightfold compared to undoped CQDs. • The fluorescence quantum yield of Zn-CQDs is 48%, higher than undoped CQDs, 37%. • With the increase in Zn2+ concentration, the PL spectrum of Zn-CQDs show a red shift phenomenon. • Zn-CQDs are ideal material for biomedical, bioimaging, optoelectronics, and catalysis. The Zn2+ doped Carbon Quantum Dots (Zn-CQDs) were synthesized with zinc citrate chelate as the precursor by a hydrothermal method. The evaluation results indicated that Zn2+ was successfully embedded in CQDs. Most of Zn2+ ions were combined with carboxyl groups on the surface of carbon dots to form Zn-O bonds and some Zn2+ ions were embedded in the interstice points of CQDs. The remaining Zn2+ were reduced to zinc atoms and adsorbed on the surface of CQDs. With the increase in Zn2+ concentration, the size of synthesized Zn-CQDs increased. When zinc ion concentration increased to 9%, the average size of Zn-CQDs grew up to 8 nm, but the size of undoped CQDs was just 1.5 nm. When Zn2+ concentration increased from 1% to 9%, the fluorescence intensity increased, while reaching above 9%, the fluorescence intensity showed a downward trend. When Zn2+ concentration was 7%, the fluorescence quantum yield of Zn-CQDs increased to 48%, but the fluorescence quantum yield of undoped CQDs was only 37%. With the increase in Zn2+ concentration, the PL spectrum of Zn-CQDs showed a red shift phenomenon. In addition, Zn-CQDs showed superior fluorescent sensing capability to Fe3+ and Hg2+, presenting greater fluorescence quenching effect on Fe3+ and Hg2+ than CA-CQDs. Therefore, Zn-CQDs demonstrated excellent fluorescence properties and can be applied in fluorescent sensor, biological imaging, optoelectronics, and catalysis fields. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09215107
- Volume :
- 264
- Database :
- Academic Search Index
- Journal :
- Materials Science & Engineering: B
- Publication Type :
- Academic Journal
- Accession number :
- 147791720
- Full Text :
- https://doi.org/10.1016/j.mseb.2020.114955