An N-nitrosation Reactivity-based Two-photon Fluorescent Probe for Specific in Situ Detection of Nitric Oxide
In situ fluorescence imaging of nitric oxide (NO) is a powerful tool for studying the critical roles of NO in biological events. However, selective imaging of NO is still a challenge because most currently available fluorescent probes rely on o-phenylenediamine (OPD) recognition site which reacts with both NO and other abundant reactive carbonyl species (RCS) and some reactive oxygen/nitrogen species (ROS/RNS). To address this problem, a new fluorescent probe NCNO based on the N-nitrosation of aromatic secondary amine was designed to bypass the interference of RCS, ROS and RNS. NCNO recognized NO with pronounced selectivity and high speed. The probe was able to image NO in live cells and deep tissues with high sensitivity owing to its two-photon excitation and red-light emission. It was hence applied to monitor NO in ischemia reperfusion injury (IRI) mice kidneys by two-photon microscopy (TPM) for the first time, and the results vividly revealed the profile of NO generation in situ during the renal IRI process.