A ratiometric fluorescent probe for the detection of peroxynitrite with simple synthesis and large emission shift and its application in cells image

Abstract

Peroxynitrite (ONOO−) is an important kind of reactive oxygen species (ROS), played an essential role in physiology and pathology. To date, various fluorescent probes for ONOO− have been constructed successfully, but these probes exhibit turn-on fluorescence signal in single channel. While, ratiometric fluorescent probes, especially those probes with large emission shift, are suitable for bioimage in two channels. Herein, a hemicyanine-based fluorescent probe named Cy-NH2 was designed and synthesized for ratiometric detection of ONOO−. The characteristics of Cy-NH2 are as follows: (1) The probe possesses a simple structure, which can be obtained by easy synthetic steps; (2) The ratiometric fluorescent probe owns large emission shift (248 nm) due to the disruption of π-conjugation system caused by strong oxidizing ability of ONOO−; (3) The probe exhibits high sensitivity to ONOO− with 1728-fold enhancement of fluorescence intensity ratio and superior selectivity for ONOO− over various potentially interfering biological analytes; (4) The ratiometric fluorescent probe is applied for the image detection of exogenous and endogenous ONOO− in living cells successfully.