A highly selective and ultrasensitive ratiometric far-red fluorescent probe for imaging endogenous peroxynitrite in living cells

Peroxynitrite (ONOO-) is involved in various physiological and pathological processes. However the detailed mechanisms of ONOO- in the biological systems remain unclear, probably due to the lack of specific and sensitive methods for detecting ONOO- in living cells. Herein, based on the intramolecular charge transfer (ICT) mechanism, we have developed a highly specific and ultrasensitive ratiometric far-red fluorescent probe RFR-PN for monitoring ONOO- in living cells. Experimental results demonstrated probe RFR-PN possesses high specificity toward ONOO- than other various bioactive molecules. Probe RFR-PN could quantitatively and sensitively detect ONOO- with the detection limit of 0.9 nM by the ratiometric fluorescence method. Surprisingly, the fast response of probe RFR-PN for ONOO- (<5 s) was achieved, and it is essential for the real-time detection of ONOO- in the living systems. Moreover, probe RFR-PN was successfully applied to the fluorescence imaging of endogenous ONOO- in living cells. (C) 2017 Elsevier B.V. All rights reserved.