A turn-on fluorescence sensor for the highly selective detection of Al3+ based on diarylethene and its application on test strips

Abstract

A novel turn-on fluorescent sensor for Al³⁺ 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 Al³⁺/EDTA. This fluorescent sensor was highly selective toward Al³⁺ 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 Al³⁺. Moreover, a test strip containing this fluorescent sensor was prepared to allow for the easy detection of Al³⁺ in water. Finally, a logic circuit was designed using four input signals (In1: UV; In2: vis; In3: Al³⁺; In4: EDTA) and one output signal.