A new bifunctional fluorescent sensor based on naphthalimide-functionalized silica nanoparticles for detection and adsorption of Cu2+ in aqueous solution

Abstract

A new bifunctional fluorescent sensor for Cu²⁺ based on naphthalimide-functionalized silica nanoparticles (NF-SiO₂) was designed and synthesized. NF-SiO₂ exhibits excellent fluorescence sensitivity and selectivity towards Cu²⁺ over other metal ions in aqueous media, and it also shows a good adsorption capacity for Cu²⁺. Moreover, the detection limit of NF-SiO₂ for Cu²⁺ is 1.5 × 10⁻⁷ M (S/N = 3) and it can be easily recovered by treatment of a solution of EDTA. These results indicate that this fluorescent sensor may find potential and favorable applications for simple detection and efficient removal of Cu²⁺ in toxicological and environmental fields.