The application provides a
rare earth flexible light-emitting film and a preparation method and application thereof. The application comprises 80-90% of a matrix and 10-20% of a
rare earth light-emitting complex, the matrix is
carrageenan hydrogel or D4 hydrogel, the
rare earth light-emitting complex is a complex formed by complexing a diphenylformamid ligand and a beta-
glucan ligand with a trivalent
europium ion, and a
structural formula is shown as formula (I). The application further provides a preparation method of the rare earth flexible light-emitting film, the rare earth light-emitting complex is added into a
carrageenan hydrogel or D4 hydrogel solution, and stirring is performed until the rare earth light-emitting complex is uniformly obtained. 3+ In the application, the two ligands of the rare earth light-emitting complex are combined through hydroxyl groups, the hydroxyl groups in the matrix structure form Eu-O coordination bonds with Eu 3+ In the application, the two ligands of the rare earth light-emitting complex are combined through hydroxyl groups, the hydroxyl groups in the matrix structure form Eu-O coordination bonds with Eu The molecular combination force is strong, the structure is stable, the preparation method is simple, green and environment-friendly, industrialization is easy to realize, and the iron
ion in water can be efficiently and sensitively identified and detected.