Construction of a Mitochondria-Endoplasmic Reticulum Dual-Targeted Red-Emitting Fluorescent Probe for Imaging Peroxynitrite in Living Cells and Zebrafish.

Peroxynitrite (ONOO - ) is one of the important reactive oxygen species, which plays a vital role in the physiological process of intracellular redox balance. Revealing the biological functions of ONOO - will contribute to further understanding of the oxidative process of organisms. In this work, we designed and synthesized a novel red-emitting fluorescent probe MCSA for the detection of ONOO - , which could rapidly respond to ONOO - within 250 s and exhibited high sensitivity to ONOO - with a low detection limit of 78 nM. Co-localization experiments demonstrated MCSA had the ability to localize into the mitochondria and endoplasmic reticulum. What's more, MCSA enabled monitoring ONOO - level changes during tunicamycin-induced endoplasmic reticulum stress. We have also successfully achieved the visual detection of exogenous and endogenous ONOO - in living cells and zebrafish. This work presented a chemical tool for imaging ONOO - in vitro and in vivo.