A simple quinoline derivatized thiosemicarbazone as a colorimetic and fluorescent sensor for relay recognition of Cu2 + and sulfide in aqueous solution

•A new quinoline derivatized thiosemicarbazone (1) was used as a Cu2 + sensor.•The sensor responses to Cu2 + through fluorescence and color changes.•The in situ formed 1-Cu2 + complex displays high selectivity and sensitivity to S2 −.•Relay recognition of Cu2 + and S2 − through fluorescence ‘on-off-on’ functionality.

A new quinoline derivatized thiosemicarbazone (1) was designed and synthesized as a colorimetric and fluorescent sensor. Sensor 1 displays highly selective and sensitive recognition to Cu2 + in aqueous solution (1‰ DMSO, HEPES 20 mM, pH = 7.4) via significant color and fluorescence changes. The on-site generated 1-Cu2 + complex exhibits high selectivity toward S2 − over other anions and thiol-containing amino acids. The Cu2 + and S2 − recognition processes are quick and reversible. Thus, rapid and highly selective relay recognition of Cu2 + and S2 − by sensor 1 in aqueous solution has been achieved.

Graphical abstractA new quinoline derivatized thiosemicarbazone (1) that displays highly selective and sensitive relay recognition to Cu2 + and S2 − in aqueous solution (1‰ DMSO, HEPES 20 mM, pH = 7.4) has been achieved.Figure optionsDownload full-size imageDownload as PowerPoint slide