A Hydrophilic Mixed Lanthanide Metal-Organic Framework Monitoring H 2 O in D 2 O.

Lanthanide metal-organic framework (Ln-MOF) luminescent sensors monitoring the H 2 O content in D 2 O are still rare. We designed and built a hydrophilic mixed Ln-MOF (Eu 0.4 Tb 0.6 -MOF) monitoring the H 2 O content in D 2 O. By designing a ligand and controlling the synthesis method, we achieved a balance between the structural stability and sensing capacity. When the H 2 O content ranges from 0 to 100%, the photoluminescence color of Eu 0.4 Tb 0.6 -MOF can change from yellow to green, which can be observed by the naked eye. The mechanism is that the photoluminescence intensity of Eu 3+ decreases faster than that of Tb 3+ when the H 2 O content increases. The sensing mechanism was studied further by transient fluorescence spectrometry.