Surfactant encapsulating N-doped carbon dots with enhanced optical properties as a selective sensor for Cr(VI) detection

Qiumeng Chen; Nan Li; Yulu Tian; Qian Liu; Xue Zou; Meikun Fan; Zhengjun Gong

doi:10.1039/d3an00517h

Surfactant encapsulating N-doped carbon dots with enhanced optical properties as a selective sensor for Cr(VI) detection

Analyst. 2023 Jun 12;148(12):2818-2824. doi: 10.1039/d3an00517h.

Authors

Qiumeng Chen¹, Nan Li¹, Yulu Tian¹, Qian Liu², Xue Zou¹, Meikun Fan¹, Zhengjun Gong^{1

3}

Affiliations

¹ Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China. gzj@swjtu.edu.cn.
² School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
³ State-province Joint Engineering Laboratory of Spatial Information Technology of High-Speed Rail Safety, Chengdu 611756, China.

PMID: 37222489
DOI: 10.1039/d3an00517h

Abstract

Detecting hexavalent chromium (Cr(VI)) is important for human health and environmental protection due to its high toxicity, carcinogenicity and persistence, but developing a sensor to selectively detect Cr(VI) remains challenging. Here, we proposed a selective fluorescent sensor for Cr(VI) detection using cetyltrimethylammonium chloride (CTAC) modified N-doped carbon dots (N-CDs-CTAC) synthesized via a post-modification strategy. Specifically, the introduced CTAC molecules could self-assemble into micelles for encapsulating fluorescent N-CDs, causing the aggregation of N-CD particles and then displaying enhanced fluorescence emission owing to the aggregation-induced emission effect. Moreover, the positively charged CTAC can interact with negatively charged Cr(VI) in the form of an anion (Cr₂O₇^2-), boosting the ability of the selective recognition of Cr(VI). Thus, a N-CDs-CTAC fluorescent probe was designed to selectively monitor Cr(VI) with an ultralow detection limit down to 40 nM, and was further used for Cr(VI) detection in real environmental samples. The fluorescence quenching mechanism of N-CDs-CTAC by Cr(VI) was attributed to dynamic quenching. The proposed assay opens an avenue for the selective detection of Cr(VI) in the environmental monitoring field.