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 H-1 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.