Synthesis, characterization and antibacterial effect of new magnetically core-shell nanocomposites

A new magnetically responsive three component nanocomposite consisting of NiFe2O4, Poly Acrylonitrite Co Maleic Anhydride (PAMA) and nanosilver was synthesized and characterized and then its antibacterial activities were tested. For the preparation of NiFe2O4@Ag, NiFe2O4 was coated by Ag and for the synthesis of NiFe2O4@PAMA@Ag, NiFe2O4 was first covered by PAMA and then silver nanoparticles were immobilized on the surface of the PAMA shell. The nanocomposites were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The antibacterial activity of the synthesized nanocomposire against some gram positive and gram negative bacteria was studiecl and compared with that of naked NiFe2O4, NiFe2O4@Ag and NiFe2O4@PAMA. The NiFe2O4@PAMA@Ag had better antibacterial activity and could be readily isolated from the aqueous solution via magnetic decantation, thereby avoiding the contamination of the environment. (C) 2015 Elsevier B.V. All rights reserved.