A Bioluminescent Probe for Imaging Endogenous Peroxynitrite in Living Cells and Mice

Peroxynitrite (ONOO^–), an extremely reactive nitrogen species (RNS), is implicated in diverse pathophysiological conditions, including cancer, neurodegenerative diseases, and inflammation. Sensing and imaging of ONOO^– in living systems remains challenging due to the high autofluorescence and the limited light penetration depth. In this work, we developed a bioluminescent probe BP-PN, based on luciferase–luciferin pairs and the ONOO^–-responded group α-ketoamide, for highly sensitive detection and imaging of endogenous ONOO^– in living cells and mice for the first time. Attributed to the BL without external excitation, the probe BP-PN exhibits a high signal-to-noise ratio with relatively low autofluorescence. Furthermore, we examine the application of the probe BP-PN using the mice model of inflammation, and BP-PN shows high sensitivity for imaging endogenous ONOO^– in inflamed mice. This newly developed bioluminescent probe would be a potentially useful tool for in vivo imaging of ONOO^– in wider physiological and pathological processes.