Azoaniline-based rapid and selective dual sensor for copper and fluoride ions with two distinct output modes of detection

Abstract An azoaniline-containing chemosensor was designed for the efficient and selective detection of Cu 2+ and F − in dual sensing modes. The diazotization reaction between 4-aminophenol and 1,3-phenylenediamine led to the formation of (E)-4-((2,4-diaminophenyl)diazenyl)phenol (A1). The hydroxyl group of A1 was protected with tert-butyldimethylsilane, leading to the target material, (E)-4-((4-((tert-butyldimethylsilyl)oxy) phenyl)diazenyl)benzene-1,3-diamine (A2). This probe showed excellent detection sensitivity and selectivity toward Cu 2+ and F − with colorimetric and turn-on fluorescence output signals. Absorption and emission studies were conducted to examine the dual sensing abilities of this probe with the sequential addition of F − followed by Cu 2+ and vice versa. These results showed that the sequential addition of F − followed by Cu 2+ resulted in excellent dual sensing responses compared to the other method of addition. A single probe can detect both Cu 2+ and F − sequentially as well as independently.