A turn-on fluorescent probe with a dansyl fluorophore for hydrogen sulfide sensing.

Hydrogen sulfide (H 2 S) is a biologically relevant molecule that has been newly identified as a gasotransmitter and is also a toxic gaseous pollutant. In this study, we report on a metal complex fluorescent probe to achieve the sensitive detection of H 2 S in a fluorescent "turn-on" mode. The probe bears a dansyl fluorophore with multidentate ligands for coordination with copper ions. The fluorescent "turn-on" mode is facilitated by the strong bonding between H 2 S and the Cu(ii) ions to form insoluble copper sulfide, which leads to the release of a strongly fluorescent product. The H 2 S limit of detection (LOD) for the proposed probe is estimated to be 11 nM in the aqueous solution, and the utilization of the probe is demonstrated for detecting H 2 S in actual lake and mineral water samples with good reproducibility. Furthermore, we designed detector vials and presented their successful application for the visual detection of gaseous H 2 S.