From F– Sensing to D2O Detection: Postprocessing Strategies Activate the Multiple Recognition Functions of Lanthanide Coordination Polymers

Lanthanide coordination polymers (Ln-CPs) are widely investigated for luminescent sensing owing to their adjustable structures and outstanding optical performance. Nevertheless, most current studies adopt a one-material-one-analyte single-function paradigm, leaving the functional expansion potential of such materials underexplored. Herein, two new Ln-CPs, L1-Sm/Eu and L1-Tb/Dy, were fabricated with cis-1,4-cyclohexanedioic acid as the ligand. A ratiometric luminescent sensor L1-Eu0.005Tb0.995 was constructed by doping trace Eu3+ into the Tb3+ framework. This material displays a highly selective and sensitive response toward fluoride ions in aqueous media, accompanied by continuous luminescence color variation from green to red, which allows naked-eye identification. Significantly, we proposed and verified a “template-platform post-modification” strategy. Using L1-Eu0.005Tb0.995 as the template platform, simple ammonia soaking triggers functional modulation and endows the material with ratiometric luminescence recognition capability for H2O–D2O mixtures, achieving a detection sensitivity of 2.5 × 10–4 v/v. This work validates the “one template, multiple sensing functions” design for Ln-CPs. On-demand luminescence functionalization can be realized via facile postprocessing, offering new insights into developing multifunctional lanthanide luminescent sensing platforms.