Multi-component hybrid organic–inorganic particles with highly dispersed silver nanoparticles in the external shell

Abstract

Complex hybrid organic–“multi inorganic” particles SiO₂@PDCL–ZrO₂@(Ag@SiO₂) (PDCL = poly(N-dicarbazolyl-lysine)) were synthesized stepwise from silica nanoparticles. First, the zirconia units were synthesized by sol–gel processing and anchored to the polyCOOH poly(dicarbazole-lysine) shell of pre-formed silica particles through metal coordination on residual COOH groups. Investigation of the particle morphology indicated a core–shell structure. A second sol–gel reaction was then carried out at the surface of the SiO₂@PDCL–ZrO₂ particles using a mixture of alkoxysilanes including an amino-substituted silane capable of chelating silver cations. Once the outer shell made of organically substituted silica was deposited, silver particles were generated by UV treatment, thus leading to an external layer of homogeneously dispersed silver nanoparticles in silica.