A novel near-infrared fluorescent probe for rapid detection of peroxynitrite with large stokes shift and imaging in living cells

Peroxynitrite (ONOO−) plays an essential role in pathological and physiological processes like signal transduction, antibacterial activity, etc. Imagining ONOO− in the living system is more important to monitor their function. We have analyzed various coumarin derivatives using DFT computations. We have designed and synthesized a coumarin chalcone-hybrid (Coumn-pHP-ONOO−) based turn-on NIR fluorescent probe for the rapid detection of ONOO− based on oxidative hydrolysis of aryl boronate group in a living system. Our probe Coumn-pHP-ONOO− shows sensitive and selective detection of ONOO− in the presence of various reactive species with a large stokes shift (149 nm) in THF/Water (6/4, v/v, pH = 7.4) solution and rapid response (<5s). The detection limit of the probe is 53.8 nM level and has a reasonable specificity in the presence of other reactive oxygen species. Moreover, our probe Coumn-pHP-ONOO− displays low toxicity, good biocompatibility, excellent permeability, and it successfully detects the ONOO− in HeLa cell.