Isophorone-based aldehyde for “ratiometric” detection of cyanide by hampering ESIPT

A new red-emitting fluorescent materials (EP1) has been designed by taking consideration of the typical asymmetrical π-conjugation structure of the isophorone skeleton, which showed a special nucleophilicity for cyanide ion. The novel probe EP1 using an isophorone-based aldehyde as color reporting group to detect CN−, which was the first time to put forward this skeleton as new color reporting group to detect analytes in the library of chemsensor. Moreover, this new saturated red-emitting fluorescent probe with a typical donor-π-acceptor structure to detect CN− was by hampered ESIPT effect, which had a prominent fluorescence “ratiometric” changes accompanied with a large stokes shifts around 150 nm. In addition, the ability of this unique probe to detect cyanide anion in living cells (A549 cells) had also been proved. These results indicated that EP1 was a highly sensitive “ratiometric” dye with promising biological applications.