HIGHLY SENSITIVE CHEMOSENSOR FOR Cu2+ AND Hg2+ BASED ON ANTHRACENE ANCHORED CALIX[4]ARENE PYRIDINE AMIDE RECEPTOR

In this study, anthracene anchored calix[4]arene pyridine amide (ant-CLX4) receptor was synthesized for the detection of Hg2+ and Cu2+ metal ions and fully characterized by spectroscopic methods. The ion binding properties of ant-CLX4 towards some selected metal ions such as Cu2+, Hg2+, Cr3+, CO2+, Ag+, Tb3+, Zn2+, Cd2+, Ni2+, Ga3+, Mn2+, Yb3+ and Gd3+ were studied by absorption and emission spectra. The ant-CLX4 demonstrated excellent fluorescence response with quenching mechanism (turn-off) in the presence of trace amount of Hg2+ and Cu2+ ions. This quenching response of ant-CLX4 receptor showing the possible binding interaction between ant-CLX4 receptor and metal ions was also observed by a fluorescence color change from bright blue to colorless in presence of metal ions as Hg2+ and Cu2+. Furthermore, the binding stoichiometry of ant-CLX4 with metal ions was confirmed a 1:1 (ant-CLX4-Hg2+ and ant-CLX4-Cu2+) binding model by Job's Plot method. The detection limits of copper and mercury ions were calculated to be 3.8 x10(-7) M and 3.3 x10(-7) M with a satisfying level for the detection of such ions in the micromolar scale, respectively. This work showed that anthracene anchored calix[4]arene pyridine amide (ant-CLX4) receptor could be used as a member of family of highly sensitive synthetic chemosensor towards toxic ions as Hg2+ and Cu2+.