Selective detection of copper ion in water by tetradentate ligand sensor

Abstract

Abstract Tetradentate ligand, 3,5-bis(((2-hydroxynaphthalen-1-yl)methylene)amino)benzoic acid (3,5-BHNMABA), was synthesized for the selective detection of copper ion. The fluorescence of the ligand in solution was quenched about 72% by Cu(II) and about 18% by Fe(II), but it was scarcely influenced by the existence of other metal ions. The ligand was chemically bound on self-assembled monolayer on indium tin oxide electrode. The as-prepared electrode exhibited the electrochemical recognition ability for metal ions: Cu(II) could be selectively caught to 3,5-BHNMABA ligand on the electrode, but Fe(II) and other metal ions did not display electrochemical response. Results indicate the selective coordination linkage of Cu(II) with the ligand both in solution and on electrode, being different from other ions. It can be concluded that the 3,5-BHNMABA-functionalized electrode is a favorable sensor for the selective detection of Cu(II) in water.