A novel methodology for fabrication of Ag–polypyrrole core–shell nanosphere using microemulsion system and evaluation of its antibacterial application

Abstract

In this study, a new microemulsion route was applied to synthesize Ag–polypyrrole (PPy) core–shell nanospheres at room temperature. In this method, colloidal Ag nanoparticles, which were prepared in a water-in-pyrrole microemulsion, were added to the aqueous solution of CTAB to form a pyrrole-in-water microemulsion. Copper(II) chloride was used in the polymerization of pyrrole monomer to produce the Ag–PPy core–shell nanocomposite, which was the product of α–α coupling reaction. The obtained nanocomposite was characterized by FT-IR, XRD, TEM and XPS techniques. TEM analysis showed that the core–shell Ag–PPy nanocomposite has a spherical structure with an average diameter of 20–50 nm. Ag core nanoparticles in the prepared Ag–PPy nanocomposite have a diameter of about 14–16 nm. XPS analysis revealed the existence of silver nanoparticles in the PPy matrix, and FT-IR analysis confirmed that Ag nanoparticles were incorporated into the PPy backbone. In order to check the antibacterial applicability of the coated silver nanoparticles, the antibacterial activity of the nanocomposite was evaluated against clinical isolates of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The results indicated that the components of the Ag–PPy core–shell nanocomposite have a synergistic effect on the antibacterial property.