Developing new Hydrazine Carbothioamide Molecules for Selective Colorimetric/Fluorometric Detection of Environmentally Essential Hg and Ag Metal Ions in Mixed Aqueous Media.

A novel colorimetric and fluorogenic probe L based on hydrazine carbothioamide and 1,8-naphthalimide moieties has been designed and synthesized for the hypersensitive detection of Hg or Ag ions. The observed probe L showed colorimetric and fluorometric responses for these studies when Hg or Ag was added to the DMSO - HEPES buffer solution (pH = 7). An interference test with other metal ions was determined, and the high selectivity of Hg and Ag did not interfere with other metal ions in colorimetric and fluorogenic methods. The possible mechanism of binding of these metal ions and the probe L 1:1 complex was determined by H NMR. Additionally, the reversibility of the affinity of probe L with mercury (Hg and silver (Ag) ions was investigated by adding NaEDTA. The naked eye detected the "Off-On" type fluorescence sensor in the presence of Hg and EDTA. The tested test strip kits provided a strong probability of probe L with high response and rapid, sensitive detection with Hg ion, which may be suitable for practical use.