A novel pyridinium-based fluorescent probe for ratiometric detection of peroxynitrite in mitochondria.

Peroxynitrite (ONOO) is a primary kind of reactive oxygen species. Excessive ONOO can induce oxidative damage to biomolecules and further results in various diseases. So, quantitative monitoring ONOO with excellent selectivity and sensitivity is imperative for elucidating its role in biological processes. In this study, a novel pyridinium fluorescent ONOO probe (CPC) has been constructed base on ICT-modulated by combining coumarin fluorophore and diphenylphosphinate recognition group. The fluorescence response of CPC for ONOO is realized via the removal of diphenylphosphinate group. The probe CPC shows prominent features for detection of ONOO including fast response rate (within 3 min), excellent selectivity and sensitivity, distinct colorimetric (red to green), and a large emission wavelength shift (105 nm). The emission intensity ration (I/I) exhibits 153-fold enhancement along with the increasing ONOO and the detection limit is as low as 1.60 × 10 M. These good response properties make CPC possible to quantitative detection of ONOO concentration. By using the strategy, the ratiometric CPC has been employed to detection of mitochondrial ONOO in live cell successfully.