Design of Ag–Au nanoshell core/mesoporous oriented silica shell nanoparticles through a sol–gel surfactant templating method

Core–shell nanoparticles based on Ag–Au nanoshell core coated with an mesoporous silica shell have been synthesized. The materials exhibit a radial pore orientation and a light absorption in the near infra-red region. [Display omitted] ► The materials are characterized by a bimetallic nanoshell coated with oriented silica mesoporous shell. ► These materials have never been reported before in such specific configuration. ► Complete description of the material synthesis. ► The nanoshell preparation involves a new procedure based on hydroxide substitution of HAuCl4 by NaOH. Core–shell nanoparticles based on Ag–Au nanoshell core and mesoporous silica shell with a radial pore orientation have been synthesized using a sol–gel surfactant templating method. The Ag/Au ratio of the nanoshells were elaborated through a galvanic replacement method performed with hydroxide gold substituted precursor using HAuCl4 as native gold precursor and NaOH as modifier. The nanoshell synthesis was optimized to provide light absorption in the near infrared “biological window” region before silica coating.