New Hg2+ and Ag+ selective colorimetric sensor based on thiourea subunits

Anthraquinone derivative (ANNCS) having two thiourea groups was synthesized. ANNCS can selectively sense Hg2+ and Ag+ through different color change, which was visually discernible by a 58 nm blue shift in the presence of Hg2+ and a broadening of the band in the presence of Ag+. The recognition mechanism is attributed to the unique structure of anthraquinone attached thiourea group and the interaction between sulfur atom and Hg2+ and Ag+.