A novel fluorescence-on fluorescent probe for ONOO- detection in HeLa cells

The reactive nitrogen species peroxynitrite (ONOO-) involve physiological and pathological processes as a significant factor. Develop a probe for monitoring the ONOO- during ferroptosis is very significant. Here, we designed and synthesized a probe TR-ONOO- based on tetraphenylene derivatives and rhodamine analogs for detection of ONOO- with fluorescence-on. Considering the strong oxidative properties of ONOO-, the carbon-carbon double bonds of bridged tetraphenylene derivatives and rhodamine analogs in the TR-ONOO- molecule are oxidized, so that the designed probe can realize fluorescence turn-on. When adding the ONOO- to the probe TR-ONOO- solution, the fluorescence intensity has increased about 40 folds and the color changed from purple to light yellow, enabling naked-eye detection of ONOO-. Furthermore, the probe TR-ONOO- can recognize ONOO- with high selectivity and fast response time. Combining with fluorescence imaging, TR-ONOO- was successfully employed for tracking endogenous ONOO- real-time and the over expression of ONOO- was effectively visualized during erastin-induced ferroptosis.