Synthesis Of Uniform Magnetite Nanoparticles Via W/O Interface System Applied As Bio-Labels

Fluorescent labeling technology is one of the most important approaches for biological marking. Recent years, magnetite nanomaterials owning special magnetic properties have been favored by researchers. The development and application of fluorescent and magnetic material have attracted much attention.Fe3O4 nanoparticles as new materials, possessing of unique physical and chemical properties, such as small size effect, surface and interface effects and macroscopic quantum tunneling effect, show a lot of sparking traits in comparison to the conventional magnetic materials. Nowadays, due to their promising prospects on practical applications, many researchers have focused on the synthesis of Fe3O4. So far, there are various methods fitting to synthesis water-soluble particles, but these methods have some shortcomings including:poor uniformity of particle size, unperfect crystal style, and poor dispersion of the products, complex synthesis process, and easily oxidization. Fe3O4 nanoparticles were synthesized via oil-water interface system, for it has't got the desired results and the former success of synthesis CdS, ZnS, NaYF4 in our lab.Hepatocellular carcinoma (HCC) is a highly malignant cancer, being the third cause of tumor-related death in the world. Thus, it is particularly necessary that to tap a quick and cheap detection method which can early predict and take treatment to the cancer. Researchers believe that it will increase the sensitivity of diagnosis and lower diagnostic costs, by combining the fluorescent labeling technology with magnetic materials. The co-doped NaYF4 nanoparticles (NPs) were produced initially and then modified by polyacrylic acid (PAA), to improve surface properties before the whole experiment. The details are showed in the following parts.First of all, Fe3O4 naopartilces were synthesised via oil-water interface system, by studying on the following factors:type and concentration of alkaline solution, type and amount of surfactants, concentration of reactants, temperature and time of reaction. The products were characterized by XRD, FTIR, VSM, TEM, HRTEM, and TGA. The results showed that:size of Fe3O4 nanoparticles was 3.5 nm. The product was strongly magnetic oil-soluble, and coated by oleic acid.Next, BSA was linked onto the surfaces of above two nanoparticles at the optimized conditions obtained by investigating their effects. The optimized conditions were that:the amount of (1M EDC usage):333μL; ratio of E/N:2:1; pH value:6.4; capacity of Pro(10 g/L BSA):300μg (NPs),400 u L (UNPs).Finally, AFP antibody Ig301 and Ig302 were conjoined to the nanoparticles respectively to prepare the immune probs. The products were characterized by SDS-PAGE electrophoresis, FTIR, Fluorescence spectrophotometer, and Lowory method. The results showed that both antibodies were successfully connected to the nanoparticles'surfaces. The amount of Ig301 was 1.77μg/mL, and Ig302 was 2.55μg/mL.