Design and synthesis of a ratiometric fluorescent chemosensor for Cu(II) with a fluorophore hybridization approach.

A new ratiometric fluorescent sensor for Cu(2+), WLN, has been developed via integrating a 1,8-naphthalimide fluorophore with 8-aminoquinoline. WLN exhibits a highly selective ratiometric response to Cu(2+) over other transition metal ions in aqueous media. Moreover, its practical ratiometric imaging ability for intracellular Cu(2+) has been confirmed in human breast adenocarcinoma cells (MCF-7 cells) using a confocal microscope.