A ‘turn-on’ fluorescent chemosensor for the detection of Zn 2+ ion based on 2-(quinolin-2-yl)quinazolin-4(3 H )-one

Abstract 2-(Quinolin-2-yl)quinazolin-4(3 H )-one ( Q ) was synthesized via the Brønsted acid-promoted tandem cyclization/dehydrogenation reaction with a good yield. Compound Q is a selective ‘turn-on’ fluorescent sensor for Zn 2+ ion without interference by Cd 2+ . The 1:1 binding model of Q to Zn 2+ was confirmed by the Benesi-Hildebrand analysis, Job’s plot analysis and a ultraviolet-visible (UV-Vis) titration experiment. Furthermore, the light-on fluorescent response can be observed by the naked eye under UV-lamp irradiation (365 nm).