A novel “off-on-off” fluorescent probe for sensing of Fe3+ and F− successively in aqueous solution and its application in cells

Abstract

We have successfully developed a bis-schiff base fluorescent probe L, linking hemicyanine aldehyde and salicylaldehyde through hydrazine hydrate, which continuously identify Fe3+ and F− in MeCN-Tris (v/v, 2:1, 10 mM, pH 7.3) solution. The probe L showed a highly selective and sensitive fluorescence “turn-on” for Fe3+ over other metal ions accompanying with the solution color change from yellow to red. Furthermore, the resulting L-Fe3+ complex detect only F− among the common various anions. The bonding mechanisms were detected by fluorescence and absorption titrations, 1H NMR titrations, HRMS and theoretical calculations. In addition, the probe has been used for liquid colorimetry and test paper colorimetric identification of Fe3+. Moreover, the probe L was used for sequentially off-on-off fluorescence imaging of Fe3+ and F− in HeLa cells.