A ratiometric naphthalimide sensor for live cell imaging of copper(I).

A new naphthalimide derivative bearing a tetrathia-azacrown for high affinity and selective binding to Cu+ was synthesised. Copper recognition properties in solution were evaluated using 1H NMR and fluorescence spectroscopy. Live cell imaging by confocal microscopy highlighted the capabilities of the new sensor for the two-wavelength detection of intracellular monovalent copper in neuronal cells.