A ratiometric fluorescent nanoprobe for ultrafast imaging of peroxynitrite in living cells.

For ratiometrically imaging peroxynitrite (ONOO-) in living cells, we devised and fabricated a novel fluorescent nanoprobe, NC-NP530/460, in this study. To achieve ratiometric fluorescence response towards ONOO-, NC-NP530/460 used 3-(2-benzothiazolyl) coumarin (Cou-Bz) as the internal reference and 1,8-naphthimide derivative (Naph-PN) as a fluorescent ONOO- probe. These compounds were incorporated into an amphiphilic block polymer called Pluronic F-127. In addition to an ultrafast response to ONOO-, NC-NP530/460 also showed great selectivity and sensitive detection (detection limit was 4.51 μM). It was important to note that NC-NP530/460 demonstrated solid performance for ONOO- fluorescence ratio imaging in living cells, highlighting its potential for ONOO--related chemical biology research.