The Role of SiO2 Shell in the Formation of Hybrid Molecular Plasmonic Core–Shell Nanoparticles

The kinetics of silicon dioxide shell formation on metal nanoparticles by tetraethoxysilane hydrolysis in the absence of catalysts is studied. The possibility of stabilizing Au–Ag alloy nanoparticles by coating with a 5 nm thick silicon dioxide shell is shown. A model of core–shell nanoparticles consisting of a metal core and a multilayer SiO₂ shell, having a phosphor based on water-soluble porphyrin encapsulated between its layers, is proposed. It is shown that encapsulation in a multilayer SiO₂ shell leads to an increase in the intensity of porphyrin luminescence.