The invention discloses a preparation method and applications of hollow 
gold nanospheres modified by 
CpG oligodeoxynucleotide. 
Cobalt chloride is subjected to reduction by adopting 
sodium borohydride,thus 
cobalt nanoparticles are obtained, 
cobalt nanoparticles are adopted for carrying out reduction on 
chloroauric acid, and thus hollow 
gold nanospheres are prepared; 
CpG oligodeoxynucleotide, a surfactant and a 
buffer solution are added into a solution of the hollow 
gold nanospheres, shaking culture is carried out, and thus the hollow gold nanosphere material modified by 
CpG oligodeoxynucleotide is obtained. According to the technical scheme, by utilizing the property that the hollow gold nanospheres have the large loading capacity, CpG is loaded through the self-
assembly effect, the synthesis method is simple, and the method is suitable for large-scale production and application; the 
cell uptake capacity of CpG oligodeoxynucleotide can be enhanced, and the 
biocompatibility is good; thehollow gold nanospheres modified by CpG oligodeoxynucleotide have the near-
infrared surface 
plasma adsorbing effect, the 
primary tumor is eliminated by utilizing the photothermal 
ablation effect, a 
tumor antigen is generated in situ, under the promoting of CpG oligodeoxynucleotide, the 
antitumor immunity of the 
whole body is induced, and the 
distant metastasis tumor is further treated.