One-pot synthesis of porous Fe3O4 shell/silver core nanocomposites used as recyclable magnetic antibacterial agents

Porous Fe3O4 shell/silver core nanocomposites featuring sustainable and recyclable antibacterial activity have been successfully prepared via a facile one lot hydrothermal method. The unique structural feature of the Ag@Fe3O4 nanocomposites with Ag embedded in porous Fe3O4 shell endows them with the ability of sustained release of silver ions. Their antimicrobial activity studies were investigated on both Gram negative Escherichia call and Gram positive Bacillus subtilis, which demonstrate that the nanocomposites are highly toxic to microorganisms and exhibit sustainable antibacterial activity. Besides, the Ag@Fe3O4 nanocomposites can be separated easily from the medium by a small magnet, which provided an effective way to eliminate the residual nanosilver from the surroundings. We finally demonstrate that the recovered nanocomposites exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent. (C) 2014 Elsevier B.V. All rights reserved