A fluorescent probe with low-background for visualization of nitroxyl in living cells and zebrafish

The development of a fluorescence probe with a low-background is essential to improve the sensitivity of the “turn-on” fluorescence response. In this paper, we present a new activatable fluorescent probe with low background for HNO sensing and imaging. The probe exhibits very weak fluorescence in solution and undergoes a cascade reaction mediated by HNO to generate highly fluorescent iminocoumarin. Under physiological conditions, the probe can rapidly and selectively responds to HNO in the presence of other biological-related species including ROS, RNS, amino acids, cations, and anions. Importantly, the probe has been successfully used to visualize HNO in living HeLa cells and zebrafish larvae.