US EPA

7432338 

Journal Article 

Selective fluorometric determination of microcystin-LR using a segment template molecularly imprinted by polymer-capped carbon quantum dots 

Qi, Z; Lu, R; Wang, S; Xiang, C; Xie, C; Zheng, M; Tian, X; Xu, X 

2021 

1 

Microchemical Journal
ISSN: 0026-265X
EISSN: 1095-9149 

Elsevier Inc. 

161 

English 

10.1016/j.microc.2020.105798 

WOS:000605202200004 

Microcystin-LR (MC-LR) is a virulent hepatotoxin that is pervasive in rivers and lakes. The contamination of water with MC-LR poses a significant threat to human life and the water ecology. Therefore, it is of great interest developing a reliable, quick, and sensitive method for the detection of MC-LR. Herein, a novel type of molecularly imprinted polymer-coated carbon quantum dot (MIP@CQDs@SiO2) fluorescence sensor is developed for the selective and sensitive determination of MC-LR. The MIP@CQDs@SiO2 fluorescence sensor was fabricated via sol–gel polymerization using L-leucine as the segment template molecule, carbon quantum dots (CQDs) as the signal materials, 3-aminopropyltriethoxysilane as the monomer, and tetraethylorthosilicate as the crosslinker. The specific recognition sites in the polymer layers could selectively adsorb MC-LR molecules, which caused fluorescence-quenching behavior of CQDs via an electron transfer process. Under optimal conditions, the linear response associated with MC-LR was 1–1000 μg/L with a limit of detection (LOD) of 0.0093 μg/L. The imprinting factor was 5.0, and the adsorption ability was 3.23 mg/g. The proposed method was proved to efficiently detect MC-LR in real water samples. In addition, the fluorescence sensor proposed in this work shows good stability in a complex matrix, excellent selectivity and sensitivity to MC-LR in real sample analysis, and remarkable potential in practical applications. © 2020 Elsevier B.V. 

Carbon quantum dot; Fluorescence sensor; MC-LR; Molecularly imprinted polymer; Sol–gel polymerization