| Metal nanomaterials show some unique properties compared to the traditional block metal material,such as quantum size effect,surface plasmon resonance,etc.and their properties have also widen the applications field.Gold and silver nanomaterials are the representative among noble metal.In this paper,we study the preparation methods,properties and applications of silver nanoparticles and gold nanocages.In this paper,silver nanoparticles were prepared by chemical reduction method,and the gold nanocages were prepared by the replacement reaction between the silver nanoparticle templates and chloroauric acid,the resulting products were hollow with thin wall.In addition,the gold nanocages with tunable UV-vis absorption peak can be tuned to near-infrared region for biomedical applications.Folic acid,also known as Vitamin M,is an essential nutrient.Due to the presence of folic acid receptors,folic acid has become a new type of targeting molecule.The folate receptor is only over-expressed in tumor cells and is almost not expressed in normal cells;it also has high affinity with folic acid.These are the condition of folic acid as a targeting molecule.In addition,folic acid has other advantages such as low price and easy accessibility compared to general targeting molecules such as some antibodies,and the folate’s fluorescence characteristics also enables folic acid and other drug or molecule complexes to serve as contrast agents for bioimaging etc.The purpose of this paper is to study the method of combining folic acid with gold nanocages by using a bridge molecule Mercapto-ethylamine.It has a thiol group at one end,which can be attached to a gold nanocage,and the other end is an amine group that can be linked to folic acid,thus gold nanocages are modified with folic acid.In this paper,UV-vis spectroscopy,transmission electron microscopy and fluorescence spectroscopy were used to characterize the samples,and it was determined that thiolated folic acid has been successfully modified on the surface of the gold nanocage.Good compatibility,photothermal conversion properties of gold nanocages,and complexes with folic acid can be used as targeted photothermic agents to treat cancer. |
