A method of preparing magnetic particles of gold

The present invention provides a new method for preparing magnetic particles of gold, it is possible to prepare a series of different color, golden magnetic particles of different sizes by adjusting the concentration of the solution, and the resulting metal magnetic particles having a good dispersibility in an aqueous solution, stability and magnetic properties, catalysis can be used in various fields, magnetic quantitative detection. The present invention features a method of co-precipitation synthesis of Fe3O4 nanoparticles prepared crude as the starting material, first citric acid-modified magnetic nanoparticles, after magnetic separation, the resulting Fe3O4 nanoparticles dispersed in ultrapure water adjusted to neutral; acid solution and then to use chlorine to polybasic carboxylic acid or a salt thereof carboxyl group-containing polycarboxylic acid ions as the reducing agent for the reduction of the Au3 + Au0 the surface of Fe3O4 nanoparticles prepared magnetic particles of gold. The present invention is simple, easy to operate, controllable characteristics.