Template free method for the synthesis of Ag–PPy core–shell nanospheres with inherent colloidal stability

Stable aqueous dispersions of silver–polypyrrole core–shell nanospheres have been synthesised in a template free method, utilizing the oxidative capabilities of ozone and silver nitrate. The core–shell nanospheres possess antibacterial and electroactive properties. Silver nanoparticles which are produced due to reduction of silver nitrate by pyrrole provide sites for the nucleation and growth of the polypyrrole shell. The morphology of the nanospheres was studied using electron microscopy and dynamic light scattering, while X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and UV–vis spectroscopy were used to study the chemical nature of the nanospheres. The electrochemical activity and thermal stability of the core–shell morphology has been studied using cyclic voltammetry and thermogravimmetric analysis, respectively. The core–shell nanospheres were studied for their antibacterial properties on Pseudomonas putida KT2440. The nanospheres reduced the viability of the strain as well as inhibited its growth.