A fluorescent and colorimetric chemosensor for Ga³⁺ and CN^–

A novel chemosensor 1 based on 4-aminobenzophenone and 2-hydroxy-1-naphthaldehyde was synthesized for the recognition of Ga³⁺ and CN^–. Chemosensor 1 displayed “turn-on” fluorescence response only to Ga³⁺, distinguishing from Al³⁺ and In³⁺, which have similar properties. Meanwhile, sensor 1 displayed color change of yellow to colorless by reacting with CN^– via a nucleophilic addition process in aqueous solution. Sensor 1 was used to quantify CN^– in real samples. Sensing processes of 1 toward Ga³⁺ and CN^– were demonstrated by the various spectroscopic studies and theoretical calculations.