An azido coumarin-quinoline conjugated fluorogenic dye: Utilizing amide-iminol tautomerism for H2S detection in live MCF-7 cells

Detection of H 2 S to analyze some diseases in living lives demands fast response, high selectivity and biocompatibility. Here we designed an azide containing coumarin attached with 8-aminoquinoline via amide backbone (ACAQ) fluorophore as the H 2 S sensing probe. Excellent response time of 6 min, high sensitivity with the limit of detection (LOD) of 14.6 nM and high selectivity with other possible interferences are revealed for ACAQ after characterized by spectroscopy, 1 H NMR titration and LC–MS measurements. The sensing strategy is explained by amide-iminol tautomerism and azide reduction. In addition, the successful visualization measurement suggests the practicability of the probe ACAQ for H 2 S detection in live samples.