A highly sensitive fluorescent sensor for Cd and Zn based on diarylethene with a pyrene unit.

A novel multifunctional diarylethene fluorescence sensor 1O containing pyrene unit was designed and synthesized. The photochromism and fluorescence photoswitching properties of this diarylethene were studied in detail by irradiation of UV/Vis lights and response of metal ions in acetonitrile solution. Diarylethene fluorescence sensor 1O has high selectivity and sensitivity for the detections of Cd and Zn. The limit of detections (LODs) for Cd and Zn were determined to be 1.85 × 10 mol L and 7.68 × 10 mol L, respectively. The binding constants (K) of 1O with Cd and Zn in acetonitrile solution were calculated to be 5.8 × 10 mol L and 6.0 × 10 mol L, respectively. The compound 1O responded to the metal ions (Cd/Zn) to form complexations with 1 : 1 stoichiometry which were verified by Job's plot and MS analysis, respectively. In addition, the fluorescence sensor 1O has been successfully applied to the detection of Cd and Zn in real water samples and processed into test strips for on-site analysis and testing.