Highly effective clean-up of magnetic nanoparticles using microfluidic technology

Abstract

The successful application of magnetic nanoparticles (MN) is highly dependent of their effective cleaning after synthesis and/or before their use in order to remove solvents, excess of surfactant, byproducts and undesired impurities that can be toxic and/or cause side effects, hindering their applicability. As manual cleaning is a time consuming and inefficient process, this work introduces the design, fabrication and testing of a simple microfluidic system able to continuously clean and separate MN. The geometrical configuration of the microfluidic channels and the experimental conditions are first optimized using finite element simulations. Next, the system is tested for the cleaning and the separation of iron oxide nanoparticles synthesized by coprecipitation. Cleaning efficiency of about 99.7 % is obtained controlling the fluid flows in the microfluidic system with residual loss of magnetic nanoparticles, demonstrating the potential of this technology for the cleaning and the separation of magnetic entities.