A rhodamine–benzothiazole conjugated sensor for colorimetric, ratiometric and sequential recognition of copper(II) and sulfide in aqueous media

•A new rhodamine–benzothiazole conjugated sensor was synthesized.•Sequential recognition to Cu2+ and S2− in neutral aqueous solution.•Ratiometric chromogenic recognition of Cu2+ and S2−.•The Cu2+ and S2− recognition are highly selective and sensitive.

A new rhodamine–benzothiazole conjugated colorimetric sensor 1 that exhibits sequential recognition to Cu2+ and S2− in CH3CN/HEPES buffer (v/v = 1:1, HEPES 10 mM, pH = 7.0) solution has been developed. Sensor 1 displays highly selective and sensitive recognition to Cu2+ with a ratiometric behavior, and the resultant 1-Cu2+ complex can act as a highly selective S2− sensor via Cu2+ displacement approach. The Cu2+ and S2− recognition processes are rapid and reversible, and the Cu2+ and S2− inputs can result in an INHIBIT logic gate.

Graphical abstractA new rhodamine–benzothiazole conjugated colorimetric sensor 1 that exhibits sequential recognition to Cu2+ and S2− in CH3CN/HEPES buffer (v/v = 1:1, pH = 7.0) solution has been developed.Figure optionsDownload full-size imageDownload as PowerPoint slide