No abstract

A coumarin-appended rhodamine derivative was prepared by reacting rhodamine hydrazide and coumarin-3-carboxylic acid, which fluorescence sensing behavior toward Zn against other metal ions was investigated in CHCN. Significantly, the rodamine-coumarin derivative exhibited highly selective and sensitive recognition toward Zn with a limit of detection (LOD) down to 10 M. Upon addition of Zn, remarkable fluorescent intensities enhanced and also clear color changed from colorless to pink. The Job's plot indicated the formation of 1:1 complex between the rhodamine-coumarin derivative and Zn. The presence of common coexisting alkali, alkaline earth, and transition metal ions showed small or no interference with the detection of Zn. The conjugate dye could be used for "naked-eye" detection of Zn.