A dual-functional coumarin-based fluorescent probe for turn off detection of Cu2+ and ratiometric detection of H2S and its applications in environmental samples and bioimaging samples

Bifunctional fluorescent probe has excited extensive interest in view of its dual-emission detection mode, favorable efficiency and low cost. Herein, a novel coumarin-based dual responsive fluorescent probe NNH was synthesized for response to Cu2+ and H2S with different fluorescence signals. This probe displayed a significant turn-off fluorescence response to Cu2+, and the limit of detection (LOD) for Cu2+ was calculated to be 0.356 & mu;M. On the other hand, NNH exhibited a ratiometric fluorescence response to H2S with highly sensitivity (detection limit 4.266 & mu;M), and the fluorescence color change from orange to cyan in the presence of H2S. The sensing mechanisms of NNH between Cu2+ and H2S were approved by Job's plot, ESI-MS analysis, and density functional theory (DFT) calculations. Besides, NNH could be served as a sensing tool for Cu2+ and H2S in environmental samples and living zebrafish.

Automated summary

A novel coumarin-based dual responsive fluorescent probe NNH was synthesized for detection of Cu2+ and H2S. The probe showed significant turn-off fluorescence response to Cu2+ and ratiometric fluorescence response to H2S, with high sensitivity and specificity. It can be used as a sensing tool for Cu2+ and H2S in environmental samples and living organisms.