A bifunctional probe for Al3+ and Zn2+ based on diarylethene with an ethylimidazo[2,1-b]thiazole-6-hydrazide unit

Abstract

A new diarylethene with ethylimidazo[2,1-b]thiazole-6-hydrazide unit was synthesized, and its photochromic and fluorescent behaviors have been systematically investigated by the stimulation of lights and metal ions in methanol. This new diarylethene exhibited high selectivity and sensitivity toward Al3+ and Zn2+. The addition of Al3+ and Zn2+ displayed excellent colorimetric response behaviour with the concomitant color change from colorless to yellow, which could be easily observed by the naked eye. Upon addition of Al3+, the fluorescence intensity was enhanced by 180–fold and the emission peak of 1O–Al3+ blue-shifted by 15 nm accompanied with a color change from colorless to bright blue. In contrast, when stimulated with Zn2+, its fluorescence intensity was enhanced by 35–fold and the emission peak of 1O–Zn2+ red-shifted by 16 nm with an evident color change from black to bright green. The LOD for Al3+ and Zn2+ were determined to be 2.97 × 10−9 mol L−1 and 5.98 × 10−9 mol L−1, respectively. Moreover, a logic circuit was constructed with the fluorescence intensity as the output signal responding to the light and chemical species as the inputs.