A novel 1,8-naphthalimide derivative as an efficient silver(I) fluorescent sensor

Novel N-n-butyl-1,8-naphthalimide derivatives with mono- or di-substitution to the C-4 position containing a N atom and a carbonyl have been synthesized as a efficient silver(I) fluorescent sensor. The ligand structures were confirmed by IR, NMR, MS, and elemental analysis. A highly sensitive spectrofluorometric method based on chelation-assisted fluorescence quenching was developed for trace-level detection, estimation and speciation studies of silver(I) in ethanol-water. The ligand exhibits emission and excitation maxima at 525 nm and 420 nm, respectively. The novel fluorescent sensor exhibited selective binding toward Ag(I) and pH insensitivity over a biologically relevant range. The interference of foreign ions was observed to be negligible.