352 Magnetite Nanoparticles for Application in Magnetic Separation of Proteins

Thursday, November 5, 2009: 4:20 PM
Pancho Villa (Camino Real Hotel)
Raúl Terrazas Reza , Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, ,, Cd. Juárez, Mexico
Carlos A. Martínez Pérez , Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, ,, Cd. Juárez, Mexico
Alejandro Martínez Martínez , Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, ,, Cd. Juárez, Mexico
Dario Bueno Baques , Centro de Investigación en Química Aplicada,, Saltillo Coahuila, Mexico
Perla E. García-Casillas , Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, ,, Cd. Juárez, Mexico
Recently, magnetic nanoparticles have been received a great attention for biomedical application such as protein separation. Such applications involve strict requirements on particle characteristics however a few studies have been focus in the effect that the particle size has over this type of application.  Based on this fact, spherical magnetite nanoparticles with particle size ranging from 16 nm to 200 nm were synthesized by three chemical methods: 1) chemical co-precipitation, 2) rapid injection technique and 3) chemcial co-precipitation under refluxing and aging conditions. The nanoparticles were coated and functionalized using different types of polymer chains attached to the particle surface. In order to increase the chain length, silica coating was applied followed by an aminosilane shell. The protein adsorption on magnetite nanoparticles coated with polymeric chains was studied. The protein adhesion for magnetite-silica, magnetite-aminosilane and magnetite-silica-aminosilane arrays was 12.5%, 79.5% and 145.75% higher than in pure magnetite, respectively. The results showed a dependence of the protein adsorption with the increase in the chain length. The magnetic properties of the Fe2O4 particles were slightly modified, having that the saturation magnetization decreased with the application of the coating; however all coated magnetite nanoparticles showed a superparamagnetic behavior, which induces a fast response to an external magnetic field. The influence of the synthesis technique on the particle morphology, size and properties and how these characteristics impact on the protein adsorption was evaluated. The maximum protein adsorption was obtained for the nanoparticles having 16 nm of size.