A turn-on fluorescence sensor for the highly selective detection of Al(3+) based on diarylethene and its application on test strips

A novel turn-on fluorescent sensor for Al(3+) based on photochromic diarylethene with a 2-hydroxybenzhydrazide unit has been successfully designed and synthesized. The photochromic and fluorescent characteristics were studied methodically in methanol under irradiation using UV/vis light and induced by Al(3+)/EDTA. This fluorescent sensor was highly selective toward Al(3+) with an obvious fluorescent color change from dark blue to blue. The Job's plot and mass spectrometry (MS) analysis indicate a binding stoichiometry of 1 : 1 between the fluorescent sensor and Al(3+). Moreover, a test strip containing this fluorescent sensor was prepared to allow for the easy detection of Al(3+) in water. Finally, a logic circuit was designed using four input signals (In1: UV; In2: vis; In3: Al(3+); In4: EDTA) and one output signal.