Novel Reversible Zn2+-Assisted Biological Phosphate "Turn-On' Probing through Stable Aryl-hydrazone Salicylaldimine Conjugation That Attenuates Ligand Hydrolysis

Abstract

A novel reversible zinc(II) chemosensing ensemble (2.Zn2) allows for selective "turn-on" fluorescence sensing of ATP and.PPi in aqueous media (detection limits:,2.4 and 1.0/AM, respectively) giving selective binding patterns: " ATP PPi > ADP >> AMP > monophosphates remaining ions tested. The " conjugated hydrazone [C=N NH R], resists hydrolysis considerably, compared, to the imine N CH2 R, pyridin-2-ylmethanamine] functionality, and generalizes to other chemoserising efforts., Prerequisite Zn2:[OphenoiNirilineNI;yri binding is selective, as determined by UV vis NMR spectroscopy; ATP or. PPi extracts ZO(2+) to regenerate the ligand fluorophore conjugate (PPi: turn-on, 512 nm; detection limit,,1.0/mu M). Crystallography, 2-D:NMR spectroscopy, and DFT determinations (B3LYP/631g*) support the nature of compound 2. 2-Hydrazinyl-pyridine-salicylaldehyde conjugation is unknown, as such; a paucity of chemosensing-Zn' binding reports underscores the novelty of this modifiable dual cation/anion detection platform. A combined theoretical and experimental approach reported. here allows us to determine both the potential uniqueness as well as drawbacks of this novel.Conjugation.