A new fluorescent sensor 1, containing furan and julolidine moieties linked through a Schiff-base, has been synthesized. Distinct "turn-on" fluorescence enhancement of 1 was observed upon the addition of F- in a near-perfect aqueous solution. The binding capabilities of 1 with F- were studied by using fluorescent spectroscopic techniques, ESI-mass analysis and NMR titration measurements. The detection limit for the analysis of F- was found to be 10.02 μM, which is below the WHO guideline (79 μM) for drinking water. Practically, the sensing ability of 1 for F- was successfully applied in real water samples. The sensing mechanism for F- was proposed to be the ICT mechanism via the hydrogen bonding, which was well explained by theoretical calculations.
Keywords: Fluoride; Fluorometric; Furan; Julolidine; Theoretical calculations.