A highly selective fluorescent sensor for Cu2+ based on naphthalimide containing aza-crown ether

The development of a fluorogenic chemosensors with high sensitivity for copper ion (Cu2+) has been receiving great attention in recent years because of their potential application in clinical biochemistry and the environment studies. In the present study, we designed and synthesized a fluorescent probe, Np-azaCE, with 1,8-naphthalimides as a core structure and 1,4-diaza-9-crown-3-ether as a copper ion tweeze, which showed selective and sensitive fluorometric change upon addition of a copper ion. The Np-azaCE chemosensor was highly selective for Cu2+ over the other metal ions with fluorescent quenching. Finally, the Cu2+ detection limit and job's plot of Np-azaCE were calculated using UV-visible spectrophotometer and fluorescence spectrophotometer.