A highly selective colorimetric and fluorescent probe Eu(tdl)abp for HS sensing: Application in live cell imaging and natural water.

Using 4-([2,2': 6', 2'- terpyridin] -4'-yl) -N, N-dimethylaniline (tdl) as auxiliary ligand and 6-azido-2,2'-bipyridine (abp) as recognition ligand, a europium complex fluorescent probe Eu(4-([2,2': 6', 2'-terpyridin] -4' -yl) -N, N-dimethylaniline)-6-azido-2,2'-bipyridine Eu(tdl)abp for efficient and specific recognition of hydrogen sulfide (HS) was successfully synthesized and characterized by NMR and MS. Eu(tdl)abp represented "on-off" fluorescence signals for HS and its color changes could be identified with naked eyes. Eu(tdl)abp had short response time (2 min) to HS, high selectivity and good anti-interference, large stokes shift (207 nm). In various samples, when HS existed, the azide group was reduced to amine group, resulting in closed fluorescence signal, and the fluorescence intensity reached the degree of quenching without being affected by other interference. At the same time, there was a good linear relationship between relative fluorescence intensity and HS concentration with the detection limit (LOD) of 0.64 μM. The sensing mechanism of Eu(tdl)abp to detect HS was characterized by H NMR and HR-MS. Eu(tdl)abp was used with success for the sensitive detection of HS in natural water and living cells.