Gold nano particle preparation method

The invention discloses a gold nano particle preparation method, which belongs to the technical field of nano material preparation. The method includes: mixing chitosan solution with chloroauric acid solution, and placing for a while before blowing air plasmas to the solution for several minutes to prepare the nano particle material. Advantages of high reactivity of the plasmas are used, and the size of the gold nano can be controlled by adjusting the proportion of the chloroauric acid to the chitosan or the reaction time of the plasmas. The method is used at the normal temperature and has the advantages of mild reaction conditions, simple process and quickness in reaction.