Water-soluble polymeric chemosensor for selective detection of Hg2+ in aqueous solution using rhodamine-based modified poly(acrylamide-acrylic acid)

We report the fabrication of a novel easily available turn-on fluorescent water-soluble polymeric chemosensor for Hg2+ ions that was simply prepared by micellar free radical polymerization of a water-insoluble organic rhodamine-based Hg2+-recognizing monomer (GR6GH), with hydrophilic monomers acrylamide (AM) and acrylic acid (AA). The chemical structure of the polymeric sensor was characterized by FT-IR and H-1 NMR spectroscopy. The apparent viscosity average molecular weight M. of poly(acrylamide-acrylic acid) [poly(AM-NaAA)] and the water-soluble polymeric chemosensor poly(AM-NaAA-GR6GH) were 1.76 x 10(6) and 6.84 x 10(4) g/mol, respectively. Because of its amphiphilic property, the water-soluble polymeric chemosensor can be used as a chemosensor in aqueous media. Upon addition of Hg2+ ions to an aqueous solution of poly(AM-NaAA-GR6GH), fluorescence enhancements were observed instantly. Moreover, other metal ions did not induce obvious changes to the fluorescence spectra. This approach may provide an easily measurable and inherently sensitive method for Hg2+ ion detection in environmental and biological applications. Copyright (C) 2015 John Wiley & Sons, Ltd.