A highly selective colorimetric and fluorescent dual-modal probe for the rapid determination of fluoride anions.

In this work, 4-(p-hydroxybenzylidenehydrazino)-N-butyl-1,8-naphthalimide (1) has been designed and synthesized as a colorimetric and fluorescent dual-modal probe for F- . Compound 1 immediately detected inorganic fluoride salts using UV/vis absorption and fluorescence spectroscopy methods, and served as a 'naked-eye' indicator for F- with high selectivity and sensitivity. Both the absorption and fluorescence spectra show excellent linearity with the concentration of F- . Real-life applications demonstrated that our proposed analytical system provided a satisfactory method for the determination of F- . In addition, the reaction mechanism of deprotonation was confirmed by 1 H NMR.