A new copper(II) selective fluorescence probe based on naphthalimide: Synthesis, mechanism and application in living cells

• A new fluorescence probe based on naphthalimide has been developed.
• The detection limit for Cu2 + was estimated to be 64 ppb.
• The sensor has practical application in living cells.

A new fluorescence probe L based on naphthalimide has been synthesized for selective and quantitative detection of Cu2 + in CH3CN:H2O (4:1, v/v) solution. L exhibited a strong green fluorescence. Upon addition of 2 equiv. of Cu2 +, the fluorescence emission shows a steady and smooth decrease until a plateau is reached with a 30-fold quenching of fluorescence intensity. In the presence of Cu2 +, the absorbance peak of L maximum at 466 nm decreased, and a new absorption band at 600 nm appeared. Under the identical conditions, other physiological and environmental important metal ions induced negligible spectroscopic changes. The 1:2 stoichiometry binding mode of L with Cu2 + was supported by the Benesi–Hildebrand analysis and ESI-MS spectra studies. The detection limit for Cu2 + was estimated to be 64 ppb. Fluorescence microscopy experiments showed that L has practical application in living cells.

A new fluorescence probe based on naphthalimide has been synthesized a fluorescent sensor for the selective and quantitative detection of Cu2 + in aqueous solution, and could be application in living cells.Figure optionsDownload as PowerPoint slide