Synthesis of Bilayer Surfactant-Coated Magnetic Nanoparticles for Application in Magnetic Fluid Hyperthermia

Nanocrystalline La_0.73Sr_0.27MnO₃ perovskite oxides with an average particle size of 26 nm were synthesized using the sol-gel method. To make water based magnetic fluid, the obtained nanoparticles were coated by self-organized bilayer surfactant containing oleic acid and sodium dodecyl sulfate as inner and outer layer, respectively. The bare and coated nanoparticles were characterized by x-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetry, and transmission electron microscopy analyses. Calorimetric analysis was used to determine the heat generation efficiency of the prepared magnetic fluid under various alternating magnetic fields. The obtained results revealed that the maximum temperature achieved by the nanoparticles is in the therapeutic temperature range which enables these materials to be used as self-controlled heating agents in magnetic hyperthermia therapy.