A novel method to prepare Au nanocage@SiO₂ nanoparticle

Gold (Au) nanocage@SiO₂ nanoparticles are prepared by a novel approach. The silver (Ag) nanocube@SiO₂ structure is synthetized firstly. Next, the method of etching a SiO₂ shell by boiling water is adopted to change the penetration rate of AuCl₄^- through the SiO₂ shell. AuCl₄^- can penetrate through silica shells of different thickness values to react with the Ag nanocube core by changing the incubation time. The surface plasma resonance (SPR) peak of synthetic Au nanocage@SiO₂ can be easily tuned into the near-infrared region. Besides, CdTeS quantum dots (QDs) are successfully connected to the surface of Au nanocage@SiO₂, which testifies that the incubation process does not change the property of silica.