چکیده
|
Hg and Cd are the two most toxic heavy metal ions that could be found in aqueous solutions. In
this study, a chemosensor based on 5-(4-((4-nitrophenyl) diazenyl) phenyl)-1,3,4-oxadiazole-2-
thiol (DOT) was reported to detect these ions simultaneously. DOT showed high selectivity to-
wards Hg ion by changing the color of the solution from beige to gold-yellow at different con-
centrations of Hg ion. In comparison, other relevant metals, such as Li+, Na+, K+, Cs+, Mg2+,
Ca2+, Al3+, Fe2+, Ag+, Cu2+, Pb2+, Ni2+, Zn2+, Cr3+, Fe3+, Pb4+, Mn2+, and Cd2+ did not affect
the color of the DOT solution as the interfering ions. Despite no changes in the color of DOT
solution in the presence of Cd ion, a solution containing DOT-Hg complex was changed from gold-
yellow to orange by adding Cd ion, providing an approach for detecting Hg and Cd ion simul-
taneously with UV–Vis and Fluorescent spectroscopy. DOT exhibited a high association constant
with a detection limit of 0.05 μM for Hg and Cd ions in an aqueous solution. The results of
quantum mechanics (QM) calculations were also consistent with the experimental observations,
which indicated that changes in the band gap could explain the various colors of DOT complex
with metal ions
|