Selective chemosensor for Hg(II) ions based on tris[2-(4-phenyldiazenyl)phenylaminoethoxy]cyclotriveratrylene in aqueous samples

A novel chemosensor, based on tris[2-(4-phenyldiazenyl)phenylaminoethoxy]cyclotriveratrylene (TPPECTV) as chromophore, has been developed for the colorimetric determination and visual detection of Hg(II) ions. TPPECTV exhibits a pronounced chromogenic behavior toward Hg(II) ions by changing the color of the solution from yellow to red-orange upon its addition, which can be easily detected with the naked-eye. Based on this sensing scheme a colorimetric method was developed, where the absorbance linearly increases as a function of the Hg(II) concentration up to 2.0 × 10−4 M, with a detection limit of 0.5 μM. The visual detection, using TPPECTV absorbed on silica, provides a simple, rapid and sensitive method and was used for the detection of Hg(II) ions in water samples with a detection limit of 5.0 μM. The colorimetric results of the detection of Hg(II) ions in environmental water samples (river water) are in good agreement with those obtained by cold vapor atomic absorption spectrometry (CVAAS).