A colorimetric and fluorescent chemosensor for selective detection of Cu 2+ based on a new diarylethene with a benzophenone hydrazone unit.

A new photochromic diarylethene based on benzophenone hydrazone has been synthesized. Its photochromic and fluorescent properties changed upon alternating irradiation with UV/Vis light and adding Cu2+ /EDTA in methanol, which showed that the diarylethene could be served as a colorimetric and fluorescent chemosensor for selective detection of Cu2+ based on internal charge transfer processes. The colorimetric and turn-off fluorescent selective detection of Cu2+ was attributed to the 2:1 complex of the diarylethene and Cu2+ . The binding constant (Ka) was 1.53 × 104  L mol-1 and the limit of detection of the diarylethene for Cu2+ was calculated to be 1.45 × 10-6  mol L-1 . In addition, the metal-responsive photochromic behavior of diarylethene was applied successfully to the construction of a molecular logic circuit.