Continuous chemical operations and modifications on magnetic γ-Fe₂O₃ nanoparticles confined in nanoliter droplets for the assembly of fluorescent and magnetic SiO₂@γ-Fe₂O₃

Abstract

We present a microfluidic platform that allows undergoing different chemical operations in a nanoliter droplet starting from the colloidal suspension of magnetic iron oxide (γ-Fe2O3) nanoparticles "NPs" (ferrofluid). These operations include: mixing, flocculation, magnetic decantation, colloidal redispersion, washing, surface functionalization, heating and colloidal assembly. To prove the platform capabilities, we produced fluorescent and magnetic nanoassemblies composed of fluorescent silica and magnetic NPs.