Facile synthesis of SiO2-Au nanoshells in a three-stage microfluidic system

The capacity to produce nanostructured materials with well-defined, specific properties in relatively Jarge quantities is crucial for the viability of emerging nanotechnologies. Core-shell plasmonic structures, such as SiO2-Au nanoshells, are a type of nanomaterial where the control of morphological properties is especially important, given the strong dependence of the plasmon frequency on their characteristic dimensions. Here we present a simple, robust and scalable process to exploit the advantages of microfluidics to manufacture these sophisticated nanostructures. We show that the main sequential steps required to obtain SiO2-Au nanoshells can be carried out in a simple microfluidic system with significant savings in time and effort, and with an improved control over the product properties, compared to a conventional batch processing operation.