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

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, H-1 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.

Automated summary

The bis-schiff base fluorescent probe L has been successfully developed for specific and sensitive detection of Fe3+ and F-, showing color change and fluorescence turn-on in solution, as well as sequential off-on-off fluorescence imaging of Fe3+ and F- in HeLa cells.