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

Abstract

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.