A colorimetric and ratiometric fluorescent probe for sulfite based on an intramolecular cleavage mechanism

ABSTRACT A colorimetric and ratiometric fluorescent sulfite probe, the levulinate of 4‐hydroxynaphthalimide, was successfully synthesized from 4‐hydroxy‐naphthalimide and levulinic acid. Through sulfite‐mediated intramolecular cleavage, the probe was converted into 4‐hydroxynaphthalimide, which when excited at 450 nm, displayed a large Stokes shift due to the intramolecular charge transfer process. The probe exhibited high selectivity and sensitivity towards sulfite over other typical anionic species (F – , Cl – , Br – , I – , HPO 4 2– , SO 4 2– , NO 3 – , AcO – , ClO 4 – , HCO 3 – ) in HEPES‐buffered solution (25 m m , pH 7.4, 50% acetonitrile, v/v). Copyright © 2013 John Wiley & Sons, Ltd.