A NIR fluorescent probe based on carbamoyl oxime with high specificity for detecting ferrous ions in food and in vivo.

Ferrous ions (Fe2+), the primary form of iron in cells, play a crucial role in various biological processes. The presence and absorption of Fe2+ in food has an important impact on human health. Proper dietary intake and iron supplementation are conducive to prevent and treat iron-related diseases. Therefore, it is of great value to develop tools that can specifically and sensitively detect Fe2+ in foods and organisms. Near-infrared (NIR) fluorescent probes have attracted much attention due to their advantages including deep tissue penetration and lower background fluorescence. Herein, a NIR fluorescent probe DICO-Fe(II) with a new recognition mechanism was constructed. DICO-Fe(II) achieves the highly specific recognition of Fe2+ through its carbamoyl oxime recognition site and exhibits high sensitivity with a limit of detection of 47 nM. DICO-Fe(II) can quantitatively detect Fe2+ with the naked eye through RGB values. It was also successfully applied to detect Fe2+ in food samples, cells, zebrafish, and mice tissues, confirming its potential as a modern analytical tool for the detection of Fe2+ in food and biological organisms.