A novel diarylethene-based fluorescent switch with a carboxamidoquinoline unit for sensing of Zn(II) ion

• A novel unsymmetrical photochromic diarylethene with a carboxamidoquinoline unit was synthesized and characterized.
• The diarylethene exhibited multi-responsive photochromic behaviors by the stimulation of Zn2+/EDTA and UV/vis and could serve as a highly selective ratiometric fluorescent chemosensor to detect Zn2+ ion.
• A logic circuit was constructed by using the fluorescence intensity as the output signal with the inputs of the combinational stimuli of Zn2+/EDTA and UV/vis.

An asymmetrical diarylethene was designed and synthesized as a ratiometric and fluorescent turn-on chemosensor for Zn2+ by conjugating diarylethene bromide with 2-amino-N-(quinolin-8-yl)acetamide. The diarylethene was highly selective toward Zn2+ ion with obvious fluorescence change. When triggered by Zn2+ ion, the diarylethene displayed a remarkable red-shift of fluorescence emission (100 nm) and an obvious increase in fluorescence intensity at 530 nm with a concomitant color change (dark to bright green). Job’s plot and electrospray ionization mass spectrometry analysis implied that the diarylethene bound to Zn2+ with a binding stoichiometry of 2:1. Additionally, the logic gate based on Zn2+/EDTA and UV/vis titration has also been described.