In conclusion, we have designed and synthesized a highly selective chemosensor based on naphthol for detection of Al3þ and Cu2þ. The chemosensor 1 exhibited a color change from yellow to orange and fluorescence enhancement with a red shift upon binding to Al3þ in acetonitrile. In addition, chemosensor 1 could detect Cu2þ with high selectivity by a color change from yellow to dark blue and a selective fluorescence quenching effect in acetonitrile.
It is proposed that the Cu2þ-sensing process involves the naphthol moiety of 1 being oxidized by Cu2þ ion to a quinine
moiety to produce 2. Furthermore, chemosensor 1 showed colorimetric and fluorescent selectivity for Cu2þ in 10% aqueous acetonitrile solution. Thus, receptor 1 could serve as a colorimetric and fluorescent sensor for the detection of Al3þ and Cu2þ ions in
aqueous solution as well as in MeCN. Future study will focus on
enhancing the water solubility of the receptor and its potential
applications in biological chemistry.