Nanoelectrokinetic bufferchannel-less radial preconcentrator and online extractor by tunable ion depletion layer

Among various preconcentration strategies using nanofluidic platforms, a nanoscale electrokinetic phenomenon called ion concentration polarization (ICP) has been extensively utilized due to several advantages such as high preconcentration factor and no need of complex buffer exchange process. However, conventional ICP preconcentrator had difficulties in the recovery of preconcentrated sample and complicated buffer channels. To overcome these, bufferchannel-less radial micro/nanofluidic preconcentrator was developed in this work. Radially arranged microchannel can maximize the micro/nano membrane interface so that the samples were preconcentrated from each microchannel. All of preconcentrated plugs moved toward the center pipette tip and can be easily collected by just pulling out the tip installed at the center reservoir. For a simple and cost-effective fabrication, a commercial printer …