Pyridinaldehyde modified luminescence metal-organic framework for highly sensitive and selective fluorescence detection of pyrophosphate

Inorganic pyrophosphate (P2O74-, PPi) plays a vital role in a variety of metabolic processes, therefore, the development of a highly sensitive and selective detection method for PPi is of great significance. In this work, a fluorescence sensor based on luminescence metal-organic frameworks (LMOFs) via covalent post-synthetic modification (PSM) was prepared and applied to the fluorescence detection of PPi. The sensor with high fluorescence quantum yield was synthesized based on Schiff base reaction between 2-pyridinecarboxaldehyde (2-PC) and TMU-17-NH2. It was designed according to the strong binding affinity between metal ion and PPi, and Cu2+ was selected as the mediating ion in this experiment. The fluorescence of TMU-PC is quenched by Cu2+ through photoelectron transfer (PET) mechanism, and the quenched fluorescence can be restored after adding PPi, forming an "on-off-on" fluorescence sensor, which can realize the sequential detection of Cu2+ and PPi. TMU-PC sensor has the advantages of fast response time, wide linear range, high sensitivity, and high specificity for PPi detection, and can be constructed as a fluorescence IMPLICATION logic gate. This work is the first attempt to prepare LMOFs via PSM for fluorescence detection of PPi, which has excellent application prospects for the clinical detection of related diseases.