A BODIPY-based dual-responsive turn-on fluorescent probe for NO and nitrite

O-phenylenediamine-BODIPY-based dual-responsive turn-on low-background fluorescence probe 1 for the detection both NO and nitrite has been successfully designed through attachment of a BODIPY dye at the meso position with the amino group of o-phenylenediamine. Probe 1 is intrinsically none fluorescent due to PET effect, however it turns quickly into highly fluorescent state upon treatment with NO in neutral condition or nitrite in acidic environment with high selectivity and low detection limit. The resulted 8-benzotriazolyl BODIPY dye could recognize biothiol such as Cys, Hcy, and GSH. In the cell imaging experiments, only blue fluorescence could be observed with probe 1 using DEA.NONOate as the source of NO and assisted by intracellular Cys and GSH. Our results may inspire and encourage researchers to use such a convenient tool for studying the effects of NO and nitrite in biological and pharmacological studies.