Fe-MOF-based fluorescent sensor with on/off capabilities for the highly sensitive detection of tert-butylhydroquinone in edible oils

• Published in: Analytica chimica acta Vol. 1278; p. 341745
• Main Authors: Wu, Zisen, Chen, Dongyan, Liu, Haodi, Lin, Anhui, Chen, Quansheng, Chen, Xiaomei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.10.2023
• Subjects: Fe(III)-Based metal-organic frameworks; Fluorescence; Ligand-to-metal charge transfer; Soybean oil; Tert-butylhydroquinone; Fluorescence; Tert-butylhydroquinone; Soybean oil; Ligand-to-metal charge transfer; Fe(III)-Based metal-organic frameworks
• ISSN: 0003-2670; 1873-4324; 1873-4324
• DOI: 10.1016/j.aca.2023.341745

In this work, a “turn off-on” fluorescent sensor was developed for highly sensitive determination of tert-butylhydroquinone (TBHQ) based on an Fe(III)-based metal-organic framework (Fe-MOF). An Fe-MOF with an octahedral structure was synthesized via a simple hydrothermal method using ferric chloride hexahydrate and 2-aminoterephthalic acid (NH2-BDC) as raw materials. The fluorescence of Fe-MOF is extremely weak owing to ligand-to-metal charge transfer (LMCT) and internal filtration effect (IFE). When the system contained TBHQ, the binding of TBHQ to Fe(III) inhibited the LMCT of the fluorescent ligand NH2-BDC to Fe(III), releasing the fluorescence of NH2-BDC and thus restoring the fluorescence. With this as the basis, a rapid, sensitive, and selective fluorescence sensor is developed for the detection of TBHQ. Under the optimal conditions, TBHQ showed good linearity with fluorescence intensity in the range of 0–1.5 × 102 μmol L−1 and a detection limit of 0.0030 μmol L−1 (S/N = 3). The selectivity, reproducibility, and stability of the developed Fe-MOF-based sensors are comprehensively studied. Finally, the practicality of the method is verified by examining the detection of TBHQ in soybean oil; the results are consistent with those obtained using conventional high-performance liquid chromatography. Scheme 1. Preparation process of Fe-MOF and its detection mechanism. [Display omitted] •An Fe-MOF-based “off-on” type TBHQ fluorescence sensor was developed.•The fluorescence of Fe-MOF is weak based on the LMCT and IFE effects of Fe-MOF itself.•The binding of TBHQ to Fe(III) inhibits the LMCT of the fluorescent ligand NH2-BDC to Fe(III).•An Fe-MOF-based test strip was designed for the rapid and visual detection of TBHQ.•Successfully determined the presence of TBHQ in soybean oil.