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

Abstract

We report the fabrication of a novel easily available turn-on fluorescent water-soluble polymeric chemosensor for Hg(2+) ions that was simply prepared by micellar free radical polymerization of a water-insoluble organic rhodamine-based Hg(2+)-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 (1)H NMR spectroscopy. The apparent viscosity average molecular weight Mη of poly(acrylamide-acrylic acid) [poly(AM-NaAA)] and the water-soluble polymeric chemosensor poly(AM-NaAA-GR6GH) were 1.76 × 10(6) and 6.84 × 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 Hg(2+) 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 Hg(2+) ion detection in environmental and biological applications.

Copolymerize Conventional Vinyl Monomers to Degradable and Water‐Soluble Copolymers with a Fluorescence Property

“…Upon their copolymerization, the copolymer shown in Scheme 1a is the most familiar structure. [ 28,29 ] However, in addition to this traditional polymerization mechanism, both Am and HEA can undergo proton transfer polymerization (PTP), resulting in a heterochain polymer. [ 30–34 ] Hence, a new type of copolymeric structure, shown in Scheme b, would be expected.…”

Enhanced Properties of the Monomer and Co-Polymer with Broad Band Absorption

“…However also, there were many water-soluble monomers are used for synthesizing water-soluble fluorescent polymers, which includes N-Nisopropylacrylamide, N-dimethyl acrylamide [7] and polyacrylamide derivatives [8]. However, most of them suffer from the same problems of the dye.…”

Graphene-Rhodamine Nanoprobe for Colorimetric and Fluorimetric Hg2+ Ion Assay

“…The obvious limitation for direct Hg 2+ ion detection by spectroscopic technique is due to the lack of significant optical response from Hg 2+ ion, on account of its closed d-shell configuration. Past few decades have witnessed remarkable progress in the development of Hg 2+ sensors. − Many attempts were directed to design portable Hg 2+ ion sensors, which includes colorimetric, fluorescent and electrochemical methods. , Probes based on organic molecules, − polymeric materials, − Au and Ag nanoparticles, etc., have been extensively investigated for this purpose. Poor solubility in aqueous solution and tedious preparation and purification steps limit the use of organic and polymer probes, whereas the high cost of noble metals holds back their widespread application.…”