On-chip synthesis of silica nanoparticle assemblies with controlled shape and size

Abstract

We describe the assembly of silica nanoparticles into superstructures with controlled shape and size. The individual nanoparticles are chemically linked to each other via silica bridges, thus providing high mechanical stability to the assembly. Key to control the size and shape of the assemblies is the confinement of the nanoparticles in highly monodisperse microdroplets that are produced in a microfluidic chip. Exploiting the high surface-to-volume ratio of the assemblies, we show an enzymatic reaction on them. To control the position of the assemblies in a microfluidic environment, we embed superparamagnetic nanoparticles into them, which allows us to move the assemblies with a simple hand magnet.

Nanomaterials and lab-on-a-chip technologies

“…Gijs's group reported the synthesis of silica nanoparticles with controllable shape and size, taking advantage of the high monodispersity of on-chip generated microdroplets to produce nanoparticles assemblies with narrow size distribution. 84 By rolling the droplets over a hydrophobic substrate they were able to obtain pillar-like assemblies which could be used as a support for catalytic precipitation reactions of fluorescent dyes.…”