Selective nano-assembly of single quantum dots on a two dimensional surface

We describe a technique for selective positioning and immobilization of individual colloidal CdSe/ZnS quantum dots (QDs) with nanometer accuracy along a two dimensional glass surface. The QDs are suspended in an aqueous solution, which is manipulated using electroosmotic flow (EOF) control. A water-immiscible resin is added to cause the QDs to separate into thin films along the channel surfaces, where they can still be manipulated. Additionally, crosslinking chemicals are introduced that locally polymerize the fluid when irradiated with UV light. These QDs are encapsulated with UV polymerization onto the surface at a desired location. We use this technique to assemble complex 3×3 arrays of pre-selected single QDs with 130 nm precision.