A far-red-emitting fluorescence probe for selective and sensitive detection of no in live cells and in C. elegans

Nitric oxide (NO), a ubiquitous intracellular and intercellular messenger molecule, plays vital roles in many physiological processes and is closely related to many diseases. Although a lot of fluorescent probes have been developed for real-time detection of NO successfully, the probes still suffer from poor tissue permeability and limited selectivity. In this study, a novel far-red fluorescent probe ZJL-3 based on rhodamine fluorescent dye was designed, synthesized, and used for NO determination. The probe contains a rhodamine as fluorophore and o-phenylenediamino as recognition unit. Upon addition of NO, the probe ZJL-3 showed an obvious far-red emission at 637 nm. The results of fluorescence spectrum experiments indicated that probe ZJL-3 exhibited desirable selectivity to NO. Furthermore, probe ZJL-3 has low cytotoxicity and was applied for the detection of exogenous and endogenous NO in RAW264.7 cells and C. elegans with satisfactory results.