Trithiocarbonate-mediated RAFT synthesis of a block copolymer: Silver nanoparticles integration and sensitive recognition of Hg2+

Heavy metal ions, such as Hg2+, pose severe risks to the environment and human health. Therefore, sensitive determination of Hg2+ is necessary. Methyl methacrylate (MMA) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) are used for the preparation of poly(MMA) (PMMA), poly(AMPS) (PAMPS), and a block copolymer, PMMA-b-PAMPS. The PMMA-b-PAMPS is further used for the synthesis of a silver nanocomposite, represented as Ag-(PMMA-b-PAMPS). The homopolymerization of MMA and AMPS is achieved by reversible addition-fragmentation chain transfer methodology using benzyl ethyl trithiocarbonate as a chain transfer agent. The synthesized polymers are characterized by several techniques including scanning electron microscopy (SEM) and X-ray diffraction (XRD). The Ag-(PMMA-b-PAMPS) is characterized by SEM, XRD, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical techniques. Further, Ag-(PMMA-b-PAMPS) is exploited to construct an electrochemical sensing platform on a glassy carbon electrode surface for the sensitive determination of toxic Hg2+ present in trace amounts. The electrochemical characteristics of Ag-(PMMA-b-PAMPS) are analyzed with and without Hg2+ using cyclic voltammetry in 0.1 M pH 7.0 phosphate buffer at 20 mVs(-1) scan rate.