A turn-off Eu-MOF@Fe2+ sensor for the selective and sensitive fluorescence detection of bromate in wheat flour

Xiaoyu Zhang; Qinqin Ma; Xinfang Liu; Huawei Niu; Lei Luo; Rongfang Li; Xun Feng

doi:10.1016/j.foodchem.2022.132379

A turn-off Eu-MOF@Fe²⁺ sensor for the selective and sensitive fluorescence detection of bromate in wheat flour

Food Chem. 2022 Jul 15:382:132379. doi: 10.1016/j.foodchem.2022.132379. Epub 2022 Feb 9.

Authors

Xiaoyu Zhang¹, Qinqin Ma², Xinfang Liu³, Huawei Niu¹, Lei Luo¹, Rongfang Li⁴, Xun Feng⁴

Affiliations

¹ College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471022, China.
² College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471022, China; College of Chemistry and Chemical Engineering, Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934, China.
³ College of Chemistry and Chemical Engineering, Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934, China. Electronic address: liuxinfang6@126.com.
⁴ College of Chemistry and Chemical Engineering, Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934, China.

PMID: 35152023
DOI: 10.1016/j.foodchem.2022.132379

Abstract

A new europium metal-organic framework (Eu-MOF) was prepared by simple hydrothermal method. The product exhibited intense red fluorescence, long fluorescence lifetime (0.454 ms) and excellent fluorescence stability. The fluorescence titration result showed that Fe³⁺ could completely quench the fluorescence of Eu-MOF, while the fluorescence quenching effect of Fe²⁺ or bromate was negligible. Considering the strong oxidizing property of bromate, a "turn off" Eu-MOF@Fe²⁺ sensor toward bromate was designed by generating Fe³⁺ due to the redox reaction. The results showed that the sensor displayed a wide linear range (0-0.2 mM), high sensitivity (LOD = 3.7 × 10^-6 mol/L), good selectivity and resistant to possible interferences in real four sample. Furthermore, the detection mechanism was investigated by PXRD, XPS and UV-Vis methods. More importantly, the Eu-MOF@Fe²⁺ sensor was further applied to detect bromate in wheat flour with satisfactory recovery (95.30%-104.38%) and accuracy (RSD < 2.85%). These results suggest that Eu-MOF@Fe²⁺ can be used as a potential sensor to detect bromate in food industry.

Keywords: Bromate; Eu-MOF; Flour; Fluorescence detection.

MeSH terms

Bromates
Europium
Flour
Fluorescent Dyes
Metal-Organic Frameworks*
Spectrometry, Fluorescence / methods
Triticum

Substances

Bromates
Fluorescent Dyes
Metal-Organic Frameworks
Europium