A turn-off Eu-MOF@Fe2+ sensor for the selective and sensitive fluorescence detection of bromate in wheat flour. (15th July 2022)

• Record Type: Journal Article
• Authors: Zhang, Xiaoyu; Ma, Qinqin; Liu, Xinfang; Niu, Huawei; Luo, Lei; Li, Rongfang; Feng, Xun
• Is Part Of: Food chemistry. Volume 382(2022)
• Publication Date: 2022-07-15
• Subjects: Eu-MOF -- Fluorescence detection -- Bromate -- Flour; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.132379
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Eu-MOF was synthesized via a simple one-step hydrothermal method. The fluorescence of Eu-MOF @Fe 2+ could be effectively quenched by bromate due to the redox reaction between bromate and Fe 2+ . The developed method possesses the advantages of good linearity, high sensitivity and selectivity, simple and visible. The fluorescence detection method was firstly applied to the determination of bromate in wheat flour. 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 Fe 3+ could completely quench the fluorescence of Eu-MOF, while the fluorescence quenching effect of Fe 2+ or bromate was negligible. Considering the strong oxidizing property of bromate, a "turn off" Eu-MOF@Fe 2+ sensor toward bromate was designed by generating Fe 3+ 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@Fe 2+ 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@Fe 2+ can be used as a potential sensor to detect bromate in food industry.