Preparation of radioactive core-shell type 198Au@SiO2 nanoparticles as a radiotracer for industrial process applications.

Silica-coated gold nanoparticles produced by gamma-ray irradiation were bombarded with neutrons in a nuclear reactor in order to activate gold nuclides into Au-198 emitting gamma radiation of 0.412–1.088MeV. The particle size ranges from 20 to 200nm. The physical integrity of the particles was examined by TEM before and after the neutron irradiation and the silica-gold particles were not affected in terms of structural appearance under gamma radiation environment. The gamma emitting NPs can be utilized as a tracer in petrochemical and refinery industrial processes where the internal temperature is extremely high and the conventional organic radioactive labeled compound would be decomposed.