A colorimetric chemosensor for the sequential recognition of Mercury (II) and iodide in aqueous media

• Selective chemosensor 1 for sequential detection of Hg2 + and I− was developed.
• The sensing mechanism for Hg2 + was supported by theoretical calculations.
• Test strips coated with 1 were applied for practical application.

A new highly selective colorimetric chemosensor 1 N′1,N′2-bis((1E,2E)-3-(4-(dimethylamino)phenyl)allylidene)oxalohydrazide was designed and synthesized as a colorimetric sensor for Hg2 +. The sensor 1 showed high selectivity toward Hg2 + in a 1:1 stoichiometric system and fast color change from yellow to orange in the presence of Hg2 +. The sensing mechanism was explained by theoretical calculations. Moreover, the resulting 1-Hg2 + complex acted as an efficient colorimetric sensor for I−, showing recovery of 1 from 1-Hg2 + complex. Furthermore, 1 and 1-Hg2 + complex could be used as practical, visible colorimetric test kits for Hg2 + and I−, respectively, in an aqueous environment. Therefore, probe 1 could be a good alternative method for onsite and real time screening of Hg2 + and I−.

A new highly selective colorimetric chemosensor 1 was designed and synthesized as a colorimetric sensor for Hg2 +. The sensor 1 showed high selectivity toward Hg2 + in a 1:1 stoichiometric system and fast color change from yellow to orange in the presence of Hg2 +. Moreover, the resulting 1-Hg2 + complex acted as an efficient colorimetric sensor for I−, showing recovery of 1 from 1-Hg2 + complex. Furthermore, 1 and 1-Hg2 + complex could be used as practical, visible colorimetric test kits for Hg2 + and I−, respectively, in an aqueous environment.Figure optionsDownload as PowerPoint slide