Development of off-on fluorescent probes for heavy and transition metal ions

A carbonyl group was positioned between 1,8-naphthalimide and di-2-picolylamine (DPA) and played a key role of displaying fluorescence enhancements with heavy and transition metal (HTM) ions through increasing the oxidation potential of the fluorophore, blocking HTM ions from sterically interacting with the naphthalimide fluorophore, and by acting as a sacrificial donor.