Multilayer Assemblies of Silica-Encapsulated Gold Nanoparticles on Decomposable Colloid Templates

Abstract

Core–shell particles with tailored optical properties are obtained via manipulation of the number of Au@SiO2 nanoparticle layers deposited onto larger polymer spheres. The surface characteristics of silica, which surrounds the gold nanoparticles, are exploited to achieve a dense and uniform nanoparticle coating. The layer‐by‐layer (LbL) self‐assembly technique yet again proves to be a worthy asset for the preparation of these novel metal‐based core–shell and hollow colloids (see Figure).

Silica‐Coated Metal Nanoparticles

“…In the last decade, there has been a focus on the solid/ dense silica coating around metal nanoparticles [3] to investigate their optical properties, [4] self-assembly for photonics, [5] or surface functionalization/conjugation for surface-enhanced Raman scattering, [6] phototherapy, [7] or colorimetric detection. [8] Very recently, silica dissolution/etching has also been emphasized to create porous structures in dense silica shells around metal nanoparticles for achieving novel hollow nanostructures, [9] novel controlled release, [10] and improved catalytic activities/lifetime.…”

Optical properties of photonic crystals composed of metal-coated spheres

“…We note that there are significant advances in the synthesis of metal-coated dielectric particles or hollow metallic nano-shells in recent years [6][7][8][9] and the optical properties of both a single nano-shell or a nano-shell cluster are also investigated experimentally and theoretically. [10][11][12][13][14][15][16][17][18][19][20] In addition to the fully fledged multiple-scattering and the coupled resonator approach, we also formulated a new k-dependent effective medium theory, which gives a good description of the optical properties of such systems in the low frequency regime. This extended effective medium formulation may be useful in other applications, and details of the mathematics are given in the Appendices.…”

From polymeric particles to multifunctional nanocapsules for biomedical applications using the miniemulsion process

“…Usually, capsules with diameters in the micrometer range up to 10 lm are obtained, only in rare cases the capsules are smaller. 47,48 One possible example is a core consisting of melamine formaldehyde, for the formation of the shell poly(allylamine hydrochloride) and poly(acrylic acid) (sodium salt) were used as electrolytes. 49 Poly(ethylene imine) microcapsules can also be prepared via the method of glutaraldehydemediated covalent LbL assembly, crosslinking the adsorbed poly(ethylene imine) layer and to introduce free-aldehyde group on the surface for the next poly(ethylene imine) (PEI) adsorption on MnCO 3 microparticles, followed by core removal.…”