A highly sensitive ON-OFF-ON fluorescent probe with three binding sites to sense copper ion and its application for cell imaging

Traditional single binding site probes for metal ions usually lack the ability to form stable products in the recognition process. Herein, a novel three binding sites ON-OFF-ON fluorescent probe, triformylphloroglucinol 3-amino-9-ethylcarbazole hydrazone was introduced to overcome this defect. After testing the optical properties of triformylphloroglucinol 3-amino-9-ethylcarbazole hydrazone, the data show that this compound is an excellent fluorescent probe for copper ion and the probe can be released by introduction of citric acid, oxalic acid, pyrophosphoric acid and sodium thiosulfate. Finally, cell permeability and live cell imaging of copper ions are also demonstrated, which is useful. (C) 2014 Elsevier B.V. All rights reserved.