AIE functionality ratiometric fluorescent probe based on quinoline-malononitrile for detection of ONOO and its application in bioimaging.

Peroxynitrite (ONOO), a highly reactive endogenous reactive oxygen species (ROS), plays pivotal roles in diverse physiological and pathological processes, the development of sensitive and reliable strategy for efficiently detecting ONOO is helpful to understand its biological functions in biological systems. Here, a novel AIEgen fluorescent probe QM-NP was developed by utilizing quinoline-malononitrile fluorophore as the light-emitting core and aryl borate moiety as the specific ONOO recognition group. Upon reaction with ONOO, QM-NP exhibits remarkable ratiometric fluorescence response with a distinct emission shift from red (630 nm) to green (540 nm), with higher specificity for ONOO compared to other analytes (ROS and RNS), rapid response (<10 s) and high sensitivity (LOD = 1.96 μM). Based on these superior spectral properties and its low toxicity, QM-NP has been successfully employed for ratiometric fluorescence imaging of ONOO in living cells and zebrafish, demonstrating its potential as a powerful tool for investigating ONOO-associated biological mechanisms.