A synthetic method to prepare a core-shell-structured Fe3O4@SiO2 as a safe nanovehicle for tumor cell targeting has been developed. Superparamagnetic iron oxide is encapsulated inside nonporous silica as the core to provide magnetic targeting. Carboxymethyl chitosan-folic acid (OCMCS-FA) synthesized through coupling folic acid (FA) with OCMCS is then covalently linked to the silica shell and re...

Monodisperse multifunctional MnFe2O4/dye/silica core/shell nanoparticles have been designed and developed. The magnetic cores act as nano-heaters in biological systems under RF field excitation and the encapsulated dyes work as local temperature probes. The silica shells enable the water-solubility and biocompatibility of the NPs and protect the encapsulated fluorophores from photobleaching.

We present a successive microfluidic approach to create and characterize hierarchical catalyst structures consisting of metal-decorated nanoparticles that are assembled into porous microparticles ("supraball" catalysts). First, using a silicon microreactor, platinum nanoparticles with a very narrow size distribution are grown and immobilized uniformly onto iron oxide/silica core-shell nanospher...

Inspired by biosilicification of glass sponges, we designed a catalytic peptide, which formed silica structures in the imidazole-buffered solution. The peptide was adsorbed selectively onto the surface of yeast cells, and the bioinspired silicification led to the formation of a cytoprotective silica shell on individual yeast cells.

We introduce biodegradable hollow silica nanocapsules embedding arrays of 3 nm gold nanoparticles. The silica shell degrades in full serum in a few hours, potentially allowing the clearance of the capsules and their contents by the efficient renal pathway, and thereby overcoming accumulation issues typical of metal nanoparticles.

We demonstrate and discuss acoustic vibrations in spherical shell particles. The particles consist of 38-nm-thick gold shells, sandwiched between an inner silica core of 456 nm in diameter and an outer silica shell of 10 nm in thickness. Employing standard and asynchronous optical sampling (ASOPS) ultrafast pump-probe experiments, we excite acoustic vibrations of the shells and detect the oscil...

Objective(s): The use of cationic surface-active agents (surfactant) in the synthesis of nanoparticles, with formation of micelle, can act as a template for the formation of meso-porous silica. Changes in the concentration of surfactants can affect the structures and properties of the resulting nanoparticles.Materials and Methods: Magnetite nanoparticles were prepared as cores using the c...

A major fabrication challenge is producing disordered photonic materials with an angle-independent structural red color. Theoretical work has shown that such a color can be produced by fabricating inverse photonic glasses with monodisperse, nontouching voids in a silica matrix. Here, we demonstrate a route toward such materials and show that they have an angle-independent red color. We first sy...

A general method has been developed for the fabrication of highly dispersed and thermally stable bimetallic Au-Ag nanoparticles (NPs) stabilized on the inner wall of a mesoporous silica shell. In our approach, gold particles were formed in the first step on carbon spheres decorated with Sn(2+) cations. Upon Ag(+) adsorption and reduction by l-ascorbic acid in the second step, specific nanoparti...

A novel core-shell composite photocatalyst, commercially available titanium(IV) oxide (TiO(2)) particles directly incorporated into a hollow amorphous silica shell, was fabricated by successive coating of TiO(2) with a carbon layer and a silica layer followed by heat treatment to remove the carbon layer. The composite induced efficient photocatalytic reactions when relatively small substrates w...