High selective and sensitive optical probe with effective recognition for Cu2+ based on a novel aniline squarylium dye

Abstract

Novel aniline squarylium dye, (Z)-3-hydroxy-2-((2-(isobutylthio) phenyl) amino) −4-((2-(isobutylthio) phenyl) imino) cyclobut-2-en-1-one (IPA) has been synthesized. It was found that IPA solution (MeCN/H2O, 4:1, v/v, 3.0 × 10−5 M) can effectively identify Cu2+ with the existence of competing cations (Ba2+, Na+, Ca2+, Cd2+, Fe3+, Cr3+, Zn2+, Co2+, K+, Ag+, Pb2+, Ni2+, Al3+, Mg2+). Meanwhile, IPA-Cu2+ induced an obvious color change, which provided a “naked eye” detection. The detection limit of IPA-Cu2+ is determined to be approximately 8.06 × 10−6 M. The job’s plot showed that the stoichiometry between IPA and Cu2+ is 1:1. In addition, the test strips of IPA showed a high selectivity to Cu2+.