Nanocomposite platform based on EDTA Modified Ppy/SWNTs for the sensing of Pb(II) ions by electrochemical method

Abstract

Heavy metal ions are considered as one of the major water pollutants, revealing health hazards as well as threat to the ecosystem. Therefore, investigation of most versatile materials for the sensitive and selective detection of heavy metal ions is need of the hour. Proposed work emphasizes the synthesis of conducting polymer and carbon nanotube nanocomposite modified with chelating ligand for the detection of heavy metal ions. Carbon nanotubes are having well known features such as tuneable conductivity, low density, good charge transport ability, and current carrying capacity. Conducting polymers are the most reliable materials for sensing applications due to their environmental stability and tuning of conductivity by doping and de-doping. Formation of nanocomposite of these two idealistic materials is advantageous over the individual material, which can help to tackle the individual limitations of these materials and can form versatile materials with ideal chemical and electrical properties. Chelating ligands are the most favorable materials due to their ability of complex formation with metal ions. The present work possesses a sensing platform based on conducting polymer and carbon nanotube nanocomposite, which is stable in various aqueous media and possess good charge transfer ability. Chelating ligands played an important role in the increased selectivity toward metal ions. Moreover, in present investigation Ethylenediaminetetraacetic acid (EDTA) functionalized polypyrrole (Ppy) and single walled carbon nanotubes (SWNTs) nanocomposite was successfully synthesized by electrochemical method on stainless steel electrode (SSE). The electrochemical detection of Pb(II) ions using EDTA-Ppy/SWNTs nanocomposite was done from aqueous media. Cyclic voltammetry technique was utilized for the electrochemical synthesis of Ppy/SWNTs nanocomposite. Ppy/SWNTs nanocomposite was further modified with EDTA using dip coating technique at room temperature. The EDTA-Ppy/SWNTs modified stainless steel electrode (SSE) exhibited good sensitivity and selectivity toward heavy metal ions [Pb(II)]. Detection limit achieved for Pb(II) ions was 0.07 μM.