A new dual colorimetric chemosensor based on quinazolinone for CNˉ, AcOˉ and Cu2+ ions

[Display omitted] •A new colorimetric chemosensor containing bioactive quinazolinone fragment is synthesized and fully characterized.•Chemosensor 2 can be utilized as a dual colorimetric chemosensor for detection of CNˉ and Cu2+ ions.•An alternative approach was developed for highly selective sensing of CNˉ based on stable complex formation of cyanide and copper ions.•The paper strips coated with the synthesized chemosensor have been prepared for the detection of CNˉ ions. This paper describes the design and synthesis of a new quinazolinone-based colorimetric chemosensor for highly selective sensing of CNˉ, AcOˉ and Cu2+ ions in aqueous acetonitrile solution. The synthesized compound as a two-faced chemosensor exhibited remarkable colorimetric responses from red to yellow in the presence of Cu2+ and red to violet in the presence of AcOˉ and CNˉ ions, which could be observed by naked eyes. In addition, an alternative approach was developed for highly selective sensing of CNˉ based on stable complex formation of cyanide and copper ions. In addition, the paper strips coated with the synthesized chemosensor have been prepared for the detection of CNˉ ions. Furthermore, the mechanism of interaction between the chemosensor and CNˉ ions has been confirmed by the 1H NMR titration experiments.