Red-emitting Fluorescent Probe for Visualizing Endogenous Peroxynitrite in Live Cells and Inflamed Mouse Model.

• A novel red-emitting fluorescent probe RFAc based on the deprotection α-keto amide group was constructed. • Probe RFAc displayed high selectivity and sensitivity for sensing ONOO‒. • Probe RFAc could image ONOO‒ in living cells and in an inflamed mouse model. Inflammation is a congenital immune protective response in living system which has tight association with various diseases. Peroxynitrite (ONOO‒) as a member of reactive oxygen species (ROS) family participates in the inflammation progress, therefore detecting ONOO‒ is very important for exploring the inflammatory-related diseases. In this work, we constructed a red-emitting fluorescent probe RFAc for monitoring ONOO‒. Utilizing the α-keto amide group as specific trigger, the probe RFAc realized selective determination of ONOO‒. Besides, it exhibited high sensitivity towards ONOO‒ with a low limit of detection (220 nM). Moreover, the detection mechanism was verified by Mass spectrometry and the intramolecular charge transfer (ICT) process was attested by density functional theory (DFT). It was important that RFAc could trace endogenous/exogenous ONOO‒ in living cells, as well detect the fluctuation of ONOO− levels in LPS-induced inflammation mouse model which could efficiently serve as a promising research tool for the inflammatory-related investigation. In this work, a novel resorufin-based fluorescent probe RFAc installing α-keto amide group as a specific trigger was elaborated constructed. The probe exhibited highly selectivity and sensitivity for detecting endogenous/exogenous ONOO‒ in living cells and was successfully employed for imaging inflammatory mice. [Display omitted] [ABSTRACT FROM AUTHOR]