A single chemosensor for the detection of dual analytes Cu2+ and S2- in aqueous media

A multifunctional colorimetric chemosensor 1, N-(2-((2,4-dinitrophenyl)amino)phenyl)-2((2-hydroxyethyl)amino)acetamide was synthesized and used to sense Cu2+ and S2- in aqueous solution. The sensor 1 showed highly selective colorimetric responses to Cu2+ and S2- by immediately changing its color from pale yellow to light green and pink, respectively, without any interference from other metal ions and anions. Especially, 1 can detect Cu2+ (10.1 mu M) below the guideline (31.5 mu M) of WHO. Moreover, the sensor 1 could be used to quantify Cu2+ ion in water samples. The sensing mechanism of Cu2+ by 1 were proposed to be a metal-to-ligand charge-transfer (MLCT) with the experimental results and theoretical calculations, and that of S2- by 1 proposed to be a deprotonation process. (C) 2016 Elsevier Ltd. All rights reserved.