Fast fluorescence sensing of aflatoxin B1 employing a europium metal–organic framework avoiding self-fluorescence interference of target

• Published in: Journal of food composition and analysis 2024-07, Vol.131, p.106223, Article 106223
• Main Authors: Liu, Mingzhu, Zhao, Zunquan, Sun, Jingran, Wang, Yonghui, Li, Xiaoli, Fang, Yanjun, Hou, Jian, Fu, Yixue, Cai, Lingchao, Wu, Jin, Bai, Jialei
• Format: Article
• Language: English
• Subjects: Actual sample detection; Antenna effect; Fluorescence spectroscopy; Luminescent metal–organic frameworks; Mycotoxin
• ISSN: 0889-1575; 1096-0481
• DOI: 10.1016/j.jfca.2024.106223

Aflatoxin B1 (AFB1) easily contaminates grain, oil, and their products, and is strongly carcinogenic. Therefore, rapid, efficient and sensitive detection of aflatoxin plays a key role in the food industry. Here, we prepared a lanthanide metal-organic framework termed Eu-TCPP, in which the ligand can effectively sensitize Eu3+ with excellent photoluminescence properties. It is worth mentioning that the fluorescence intensity of Eu-TCPP is at 617 nm, which can avoid the interferences of AFB1 self-fluorescence emitting in the range of 400 nm–500 nm. Eu-TCPP can efficiently detect AFB1 without using antibody or biomolecular modifications, exhibiting a rapid response of 60 seconds and a limit of detection (LOD) at 11.63 ppb. The Eu-TCPP sensor also has satisfactory performance for determining AFB1 sensitively in real oil samples. In addition, the mechanism of the excellent detection performance of Eu-TCPP has been investigated using density-functional theory (DFT) calculations combined with experimental analysis. The results show that the LUMO energy level of the ligand is higher than that of the aflatoxin, which causes the electrons transfer toward the targets, and results in the reduction of the fluorescence intensity. Therefore, our proposed Eu-MOF materials based on the "antenna effect" have great potential for the development of simple, fast, and sensitive small-molecule sensors, and offer a promising prospect in POCT applications. [Display omitted] •A novel Eu3+-based luminescent MOF (Eu-TCPP) was synthesized for aflatoxin sensing.•Eu-TCPP can selectively detect aflatoxin B1 without using antibody or biomolecular modifications.•Eu-TCPP showed rapid and efficient quenching response toward aflatoxin B1.•Eu-TCPP can avoid the interferences of aflatoxin B1 self-fluorescence.•The Eu-TCPP sensor was successfully applied to detect aflatoxin B1 in oil samples.