Application of a Colorimetric and Near-Infrared Fluorescent Probe in Peroxynitrite Detection and Imaging in Living Cells.

Peroxynitrite (ONOO) plays a vital role in pathological and physiological processes, and an excessive amount of ONOO causes various diseases. Developing a specific and sensitive method for the detection of ONOO in biological systems is significant. Herein, we reported a novel colorimetric and near-infrared fluorescent probe (pyridin-4-ylmethyl (Z)-2-cyano-2-(3-((E)-4-hydroxystyryl)-5,5-dimethylcyclohex-2-en-1-ylidene)acetate diphenyl phosphinate group ()) based on isophorone and phosphinate groups for ONOO detection. The probe displayed excellent selectivity toward ONOO compared with other relevant analytes. It showed a good linear relationship between the fluorescence intensity at 670 nm and ONOO concentration (0-10 μM) with a low detection limit (53 nM). Importantly, the probe was a colorimetric and near-infrared fluorescent probe suitable for ONOO detection. Furthermore, the probe could be used for imaging ONOO in HepG2 cells.