Chromone-based fluorescent probe for peroxynitrite imaging in Arabidopsis thaliana

As a typical reactive nitrogen species, peroxynitrite (ONOO−) plays an important role in cells and organisms. But in plants, information on the role of endogenous ONOO− remains limited. In order to explore its functions, it is necessary to probe ONOO− in biological systems, especially in plants. In this paper, we report RAW-A, a chromone-based fluorescence probe, exhibits a highly selective and sensitive response to ONOO−. It is worth noting that RAW-A has good water solubility, which is beneficial for the application of biological systems. RAW-A can respond to ONOO− even at low concentrations of ONOO−, indicating that the probe is expected to monitor ONOO− in real-time in living systems. In addition, confocal imaging experiments show that RAW-A can image endogenous and exogenous ONOO− in Arabidopsis thaliana root besides HeLa cell. It shows that RAW-A has the potential to be an imaging tool for studying the biological roles of ONOO− in plants. To our knowledge, RAW-A is the first fluorescent probe with highly selective and sensitive response to ONOO− in plants.