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.