Selective Cu2+ detection by a novel fluorescence hydrazone-Base probe in aqueous media

This article describes the novel hydrazone derivatives bearing chromeno[2,3-c]pyrazole heterocycles synthesis via pyrazol-3-one elimination and the properties of their fluorescence emission. The photophysical properties of the novel dyes were studied in the presence of different solvents, and 31 various ions, which demonstrated hydrazone 4b showed a distinct response toward Cu2+ in rather aqueous media with a good limit of detection. This probe forms a 1:2 complex with Cu2+, and fluorescence enhancement occurs by C--N isomerization inhibition. Also, the results exhibited that 4b with moderate cytotoxicity is a simple and valuable probe for selective fluorescence sensing of Cu2+ ions in both experimental and real samples.