Development of a fluorescent strategy for quantification of fluoride ions in foods and toothpaste

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-11, Vol.448, p.137631, Article 137631
• Main Authors: Zhang, Yaping, Qu, Yi, Zhang, Yuqi, Gao, Ya, Wang, Le
• Format: Article
• Language: English
• Subjects: Fluorescent probe; Fluoride ion; Naphthalimide; Real sample detection
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.137631

Design and synthesis of a novel fluorine fluorescent probe based on 1,8-naphthalimide. The strong Lewis acidic boron atom was introduced for sensing fluoride with the Lewis base character, the PET process was inhibited, and the fluorescence intensity was enhanced. Probe detects fluoride ions in liquid and solid samples. [Display omitted] •A 1,8-naphthalimide-based fluorescent probe was designed for detecting F−.•The probe identified F− with 33 nM detection limit and good selectivity.•The probe can rapidly detect F−content in several foods and toothpaste. Fluoride is one of the key chemical elements in human life and chemical industry, which also shows the high toxicity. A fluorescent probe (ZYP-1) based 1,8-naphthalimide has been prepared for fluoride ions detection, and exhibited high selectivity and sensitivity towards real samples. 19F NMR and 1H NMR titration was further determined the interaction between analyte and ZYP-1, and show the strong Lewis acidic boron atom of probe can complex basic fluoride. Theoretical calculations demonstrate that the coordination process will inhibit the photoinduced electron transfer (PET) from fluorophore to boron center that results in the increased fluorescence intensity at 540 nm. The limit of detection (LOD) of ZYP-1 for F− was found as low as 33 nM in acetonitrile. The probe can successfully applied in various liquid and solid samples of foods (fish fillets, tea leaves, water, and milk) and toothpaste to detect fluoride, which render broad application prospect.