Reversible Ni2+ fluorescent probe based on ICT mechanism and its application in bio-imaging of Zebrafish

Small-Molecule Fluorescent Probes for Binding- and Activity-Based Sensing of Redox-Active Biological Metals

“…Wang and coworkers reported morpholine-bearing naphthalimide NIC (357), which exhibits quenching of the green emission peak upon addition of Ni(II). 595 The authors identified the formation of a 1:1 complex with Ni(II) binding to the hydroxyl group at the imide nitrogen, and to one of the imide oxygens, preventing the ICT crucial for naphthalimide fluorescence. The morpholine group favors the localization of the sensor to the lysosomes, confirmed by imaging studies in HeLa cells.…”

“…Dye 356 was applied to zebrafish, with lower fluorescence observed upon incubation with Ni(II)-containing medium. Wang and co-workers reported morpholine-bearing naphthalimide NIC ( 357 ), which exhibits quenching of the green emission peak upon addition of Ni(II) . The authors identified the formation of a 1:1 complex with Ni(II) binding to the hydroxyl group at the imide nitrogen, and to one of the imide oxygens, preventing the ICT crucial for naphthalimide fluorescence.…”

The design strategies and biological applications of probes for the gaseous signaling molecule hydrogen sulfide

“…Naphthalimide is a well-known D-p-A structure fluorophore considering its good photochemical stability, high quantum yield, cell transmissibility, and visible emission (B550 nm), and thus was selected as the favorable fluorescent scaffold. 29 Based on this, Fu's group developed a two-photon probe 2 (Fig. 2), i.e., 4-azido-6-sulfo-N-hex-adecyl-1,8-naphthalimide, sodium salt, which has cell surface specificity and could be used to investigate the extracellular release behaviors of H 2 S. 30 The authors linked the azide group directly to the 4-position of naphthalimide and formed a ''pull-pull'' system, which resulted in the fluorescence quenching of naphthalimide due to the intermolecular charge transfer (ICT) process being blocked.…”

“…Naphthalimide is a well-known D–π–A structure fluorophore considering its good photochemical stability, high quantum yield, cell transmissibility, and visible emission (∼550 nm), and thus was selected as the favorable fluorescent scaffold. 29 Based on this, Fu's group developed a two-photon probe 2 (Fig. 2), i.e.…”