Synthesis and Characterization of Fe-Ag Alloy Nanoparticles with Combination of Magnetic and Optical Properties for Liposomes

Fe-Ag alloy nanoparticles (NPs) with combination of optical and magnetic properties have been prepared by microemulsion method for the application as functional nanoparticles in drug-carrying liposomes. The size of the Fe-Ag alloy NPs can be controlled by adjusting the molar ratio of water-to-surfactant in the water-in-oil microemulsion. The Fe-Ag alloy NPs have been characterized with transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), dynamic light scattering, X-ray diffraction (XRD), energy-dispersive X-ray spectrum (EDS), fluorescence and absorption spectroscopy, and superconducting quantum interference device (SQUID) magnetometer. It was demonstrated that the Fe-Ag alloy NPs contained both iron phase and silver phase and exhibited superparamagnetic behavior when the temperature was higher than 51 K. The optical properties of the Fe-Ag alloy NPs could be influenced by the initial molar ratio of Fe/Ag and the optical intensities decreased with the increase in the Fe content. The magnetic property of the Fe-Ag alloy NPs could also be influenced by the molar ratio of Fe/Ag, as well as the molar ratio of water-to-surfactant in the microemulsion. The saturation magnetization of Fe-Ag alloy NPs increased with the increasing of the Fe content and the size of the NPs.