Construction of Lanthanide Coordination Polymers Containing Water Hydrogen Bond Units for Ratiometric Luminescence Sensing of the H₂O–D₂O System

High-purity heavy water is crucial in core areas, such as nuclear energy, military, and chemical and biological research, and accurate detection of its content and purity is of great significance. Here, we report a novel lanthanide coordination supramolecular framework (Ln-CSF), which is assembled from two-dimensional coordination polymer layers and hydrogen-bonded helical chains. The correlation between the structure and properties endows it with luminescent sensing capabilities. The doped Ln-CSF exhibits excellent dual-wavelength luminescence performance, and a series of luminescence test results in the D₂O-H₂O mixed system show that L1-Eu_0.01Tb_0.99 can qualitatively differentiate and detect H₂O and D₂O with the naked eye. It also has the advantages of low detection limit, recyclability and reusability, short reaction time, rapid detection, etc. In addition, making it into a composite film with PMMA also demonstrates its portable and stable practical application performance. The significance of this work is the synergistic construction of a novel Ln-CSF based on coordination and hydrogen bonding interactions. More importantly, it explores the correlation between structure and performance, providing experience and new ideas for the research of lanthanide luminescent materials.