An ESIPT-based fluorescent probe with large Stokes shift for peroxynitrite detection in HeLa cells and zebrafish

The quick coupled reaction of nitric oxide (NO) with superoxide free radicals (·O₂⁻) produces peroxynitrite (ONOO⁻), it is a powerful biological oxidant. And according to interact with proteins, lipids, nucleic acids and other organisms, the ONOO⁻ eventually leads to all sorts of diseases, for instance, Alzheimer's disease, diabetes, cancer, inflammation. To fully understand the multiple pathological processes of ONOO⁻ in vivo, it is imperative to exploit effective tools to realize the precise, fast and sensitive detection of endogenous ONOO⁻. We described a novel fluorescent probe named YV in this work, covering the synthesis, characterization and biological application. YV can detect ONOO⁻ by means of fluorescence imaging. Because of the borate group cleavage, YV exhibited a fluorescence intensity change toward ONOO⁻. It was, the principle of ESIPT that resulted in fluorescence enhancement. The probe YV shows a series of advantages such as high selectivity, fast response, significant Stokes shift and low detection limit. Fluorescence imaging can be used to identify variations in ONOO⁻ in Hela cells and zebrafish. YV will be a robust imaging tool for detecting endogenous ONOO⁻.