A novel ratiometric fluorescent probe for highly sensitive and selective detection of peroxynitrite and its application for tracing endogenous peroxynitrite in live cells

Peroxynitrite (ONOO-) is a reactive and short-lived biological oxidant endogenously generated in biosystems, and its excessive production is related to various diseases. However, the functional mechanisms of ONOO- are not fully understood. Here, we present a novel ratiometric fluorescent probe CPD-ratio for the accurate detection of ONOO- under single wavelength excitation. This study showed that the probe CPD-ratio can achieve the ratiometric detection of ONOO- with rapid response, and it possessed excellent selectivity and sensitivity (detection limit was calculated to be 47 nM). These properties and its non-toxicity demonstrated that probe CPD-ratio could be potentially employed to accurately monitor ONOO- levels in biological systems. We have thoroughly demonstrated the utility of the probe CPD-ratio for ratiometric bioimaging, because it has been effectively used to trace the exogenous and endogenous ONOO- in live cells.