A novel hexahydropyridazin-modified rhodamine fluorescent probe for tracing endogenous/exogenous peroxynitrite in live cells and zebrafish

As a reactive nitrogen species (RNS), peroxynitrite (ONOO-) is known for its crucial functions in biological systems. Excessive formation of ONOO- is very closely related to the pathogenesis of a series of diseases, and thus, effective methods are needed for highly sensitive detection of ONOO-. Herein, a simple fluorescent probe RHHP-PN was proposed to detect ONOO-, and manifested obvious color changes from colorless to red in less than 10?s. Besides, it is not only suitable for quantitative detection of ONOO-, but also satisfactory in distinguishing ONOO- from other related species. What is particularly noteworthy is the fluorescence bioimaging for tracing endogenous and exogenous ONOO- in living cells and zebrafish. Therefore, probe RHHP-PN could be used as an imaging tool to visualize intracellular ONOO- in biological systems.