Recyclable silver-magnetite nanocomposite for antibacterial application

Surface modification of magnetite nanoparticle (MNP) with cysteine for efficient conjugation with silver nanoparticle (AgNP) is herein presented. This novel nanocomposite was prepared via a specific binding interaction between thiol groups of cysteine coated on the MNP and the surface of AgNP. Transmission electron microscopy indicated the formation of the nanocomposite with 18-24 nm silver nanoparticles and 8-12 nm magnetite nanoparticles. Energy dispersive spectrometry verified the presence of both Ag and Fe in the nanocomposite. After repetitive adsorption-desorption-washing process, the nanocomposite retained higher than 90% antibacterial efficiency against Escherichia coli K12 for at least five recycling cycles. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.