A multifunctional Schiff base as a fluorescence sensor for Fe and Zn ions, and a colorimetric sensor for Cu and applications.

Chemosensors play important parts in the selective recognition of ions, which is widely applied in various fields of environment, industry and biological sciences. In this work, a chemosensor for multi-metal ions based on rhodamine B derivative was synthesized, which could selectively recognize various metal ions in different solvent system. The addition of Cu caused the color change from colorless to pink in EtOH/HO (v/v=1:1) solvent system, which could be quickly identified by the naked eyes with a detection limit of 8.27×10M. In ethanol solution system, the addition of Fe and Zn caused different fluorescence changes with the detection limit of 2.12×10M and 6.64×10M respectively. The binding ratios are 1:1 (1-Cu), 2:1 (1-Fe) and 1:1 (1-Zn), respectively. Meanwhile, the probe 1 was used to detect the trace metal ions in real water samples. Besides, the probe 1 showed sensitive fluorescence signals for Fe in biological cells. The experimental results further verify the application value of the sensor.