title: Continuous-flow separation of nanoparticles by electrostatic sieving at a micro-nanofluidic interface.
abstract: Continuous-flow separation of nanoparticles (NPs) (15 and 39 nm) is demonstrated based on electrostatic sieving at a micro-nanofluidic interface. The interface is realized in a poly(dimethylsiloxane) device with a nanoslit of 525 nm laterally spanning the microfluidic channel (aspect ratio of 540:1). Within this nanoslit, the Debye layers overlap and generate an electrostatic sieve. This was exploited to selectively deflect and sort NPs with a sorting purity of up to 97%. Because of the continuous-flow operation, the sample is continuously fed into the device, immediately separated, and the parameters can be adapted in real time. For bioanalytical purposes, we also demonstrate the deflection of proteins (longest axis 6.8 nm). The continuous operation mode and the general applicability of this separation concept make this method a valuable addition to the current Lab-on-a-Chip devices for continuous sorting of NPs and macromolecules.
authors: Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld University, Germany. jan.regtmeier@physik.uni-bielefeld.de
authors: Jan
authors: J
authors: Regtmeier
authors: Jörg
authors: J
authors: Käsewieter
authors: Martina
authors: M
authors: Everwand
authors: Dario
authors: D
authors: Anselmetti
mesh_terms: D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000032:analysis / Q000302:isolation & purification*; D055672:Static Electricity
chemical_list: D011506:Proteins