Coumarin-Based Turn-on Fluorescent Probe for Copper(II) Detection and Its Application in Cell Imaging

A new coumarin-based Cu2+ probe (Cou-P) according to the Cu2+ coordination induced hydrolysis mechanism has been developed. Cou-P exhibits a highly selective turn -on response to Cu2+ over other transition metal ions in aqueous media. The recognition mechanism of Cou-P for Cu2+ was comfirmed by UV-Vis, fluorescence and mass spectrometry. The results show that Cou-P first forms Cou-P/Cu2+(1:1) complex, and Cou-P/Cu2+ complex is further catalyzed to 3 -(carboxylic acid)-7-(diethylamino)-coumarin (Cou-COOH) by excessive Cu2+. Cou-P has low cytotoxicity and good membrane permeability. It has been successfully used to detect Cu2+ in MCF-7 cells.