A convenient tool for real-time detection of iron content in human food

Abstract

A fluorescent sensor, (E)-2- (((5-(5-methoxy-1H-benzo[d]imidazol-2-yl)thiophen-2-yl)methylene)amino)phenol (OMTP), was designed for direct application to the surface of onions using a smartphone for real-time monitoring of iron content. The detection limit was as low as 0.014 μmol/L. The probe OMTP exhibited weak fluorescence in EtOH/H2O (49:1) due to its non-planar molecular structure. However, it showed strong green fluorescence at 530 nm, attributed to an enhanced Intramolecular Charge Transfer (ICT) effect after the addition of Fe 3+/2+ . Probe OMTP had a wide range of applications: (1) real-time monitoring of iron absorption processes during the growth of onions and bean sprouts; (2) rapid detection of iron content in beverages such as wine using test strips; (3) visual detection of iron on the surface of fruits and vegetables. A fluorescent probe for rapid and portable iron monitoring has been successfully synthesized, enabling nonprofessionals to conduct self-inspections of their dietary iron intake at home. The reaction rate was calculated by calculating the potential energy surface (PES), and the results provided a basis for the rational design of probes in terms of kinetics and interference resistance. This probe has significant potential for applications in the fields of food and agriculture.Research on ab initio calculations 30 for probe design is relatively scarce, making it difficult to predict detection performance in advance. Therefore, the design of theoretical computational models for probes is also essential 31 . The 2thienylbenzimidazole framework represents a conjugated system with a non-centrosymmetric structure 32 . Upon appropriate substitution, it can serve as a promising platform for developing materials that exhibit pronounced nonlinear optical (NLO) 33 effects. In particular, conjugated molecules bearing substituents at the 6-and 13-positions show significant NLO activity 34 . The fluorescence performance of the donor-π-acceptor (D-π-A) structure formed by introducing electron-withdrawing and electron-donating groups at both ends of the conjugated system