A selective tripodal chemosensor based on 1,1,1-tris[(7-nitrobenzofurazan-4-yl)-n-1-aza-5-oxahexanyl] propane (1, TNFHP) has been developed for the detection of Hg(II) ions. This receptor exhibits a pronounced chromogenic behavior toward Hg(II) ions by changing the color of the solution from yellow to dark 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) ions concentration up to 5.0 x 10(-5) M, with a detection limit of 0.1 mu M. The colorimetric results of the detection of Hg(II) ions in environmental samples are in good agreement with those obtained by cold vapor atomic absorption spectrometry. This chemosensor has also been applied for detection of Hg(II) ions in cosmetics samples.
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