Surface Functionalized Luminescent Nanocrystals Electrostatically Assembled onto a Patterned Substrate

Methods: Properly synthesized luminescent colloidal CdSe@ZnS NCs, coated by a silica shell, have been functionalized introducing specific chargeable moieties at their surface. At the same time, a patterned substrate has been fabricated by NanoImprint Lithography (NIL) on a polymer film deposited on a silicon substrate, resulting in polymeric structures alternating to bare silicon regions. Such "polymer-free" area have been further functionalized with charged bifunctional molecules to form a self-assembled monolayer (SAM), able to attract, by electrostatic interactions, the silanized NCs.

Background: In the last decades, the enormous interest in 2/3D nanocrystal (NC) architectures boosted the development of many and diverse techniques which allowed to precisely positioning the nanoparticles on substrates. The tremendous importance of such NC organizations is due to the novel collective properties arising from inter-particle interactions that emerge in these artificial materials, with promising application in opto-electronics, photonics and biomedicines.