Nitrogen-doped carbon quantum dots as fluorescent probe for "off-on" detection of mercury ions, l-cysteine and iodide ions

Hao Huang; Yuhui Weng; Lihao Zheng; Bixia Yao; Wen Weng; Xiuchun Lin

doi:10.1016/j.jcis.2017.07.076

Nitrogen-doped carbon quantum dots as fluorescent probe for "off-on" detection of mercury ions, l-cysteine and iodide ions

J Colloid Interface Sci. 2017 Nov 15:506:373-378. doi: 10.1016/j.jcis.2017.07.076. Epub 2017 Jul 20.

Authors

Hao Huang¹, Yuhui Weng², Lihao Zheng¹, Bixia Yao¹, Wen Weng³, Xiuchun Lin⁴

Affiliations

¹ College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China; Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Zhangzhou 363000, China.
² College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China.
³ College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China; Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Zhangzhou 363000, China. Electronic address: weng_wen@126.com.
⁴ College of Environmental and Engineering, Putian University, Putian 351100, China. Electronic address: 420186900@qq.com.

PMID: 28750239
DOI: 10.1016/j.jcis.2017.07.076

Abstract

The application of fluorescent nanoparticles to the detection of inorganic ions and organic compounds has been attracted wide attention recently. In this paper, an "off-on" method for highly sensitive and selective detection of Hg²⁺ and l-cysteine (l-Cys) or Hg²⁺ and I^- using home-made nitrogen-doped carbon quantum dots (N-CQDs) as fluorescent probe was reported. The N-CQDs with a fluorescence quantum yield of 42.2% were prepared using tartaric acid, citric acid and ethanediamine as the precursors in the oleic acid media. The fluorescence of the obtained N-CQDs could be quenched selectively and sensitively by the addition of Hg²⁺ (turn-off) with a detection limit of 83.5nM. When l-Cys or I^- was added into the N-CQDs-Hg²⁺ system, the fluorescence was recovered effectively (turn-on). This process could be used to the detection of l-Cys or I^- with a detection limit of 45.8 and 92.3nM, respectively.

Keywords: Carbon quantum dots; Fluorescent probe; Iodide ions; Mercury ions; l-Cysteine.