An acridone-derived fluorescent off-on probe for detection and in vivo imaging of nitroreductase

Understanding the functions of enzymes in various physiological processes is important, but design signaling probes for fast analysis enzymatic activity particularly challenging. Herein, a fluorescence-enhanced probe, 10-methyl-2-nitro-acridone (MNA), was synthesized and applied to analyze nitroreductase (NTR) vitro vivo . The detection mechanism based on nitro group MNA reacting toward NTR with high reactivity generating 10-methyl-2-amino- acridone (MAA) accompanied by an obvious fluorescence signal enhancement at 525 nm emission. probe shows low cytotoxicity, response, selectivity sensitivity limit as 150 ng·mL −1 also employed two-photon imaging zebrafish revealing distribution NTR. Versus existing probes, proposed favorable analytical performance including near-infrared light excitation no other byproducts produced after reaction. superior properties this allow it become candidate biosystems.