Tune Metal Ion Selectivity by Changing Working Solvent: Fluorescent and Colorimetric Recognition of Cu2+ by a Known Hg2+ Selective Probe

A known Hg2+ selective rhodamine B derivatised probe 1 was reinvestigated as a colorimetric and fluorescent probe for Cu2+ through changing the applied solvent media. Probe 1 exhibited good selectivity and sensitivity to Cu2+ in CH3CN-H2O (7:3, v/v, HEPES 10 mM, pH 7.0) solution with a detection limit of 9.74 × 10 −7 M. The Cu2+ sensing event was proved to be irreversible through hydrolysis of 1 to release rhodamine B