A Capillary-based Preconcentration Device by using Ion Concentration Polarization through Cation Permselective Membrane Coating

Abstract

Ion Concentration Polarization (ICP), occurring near the ion permselective membrane, is considered to be one of the most intriguing phenomenon in the study of electrokinetics. Both ion enrichment and depletion zones are found to be formed at the anodic side of the microchannel due to the characteristic of the electrical repulsion force which is generated near the ion permselective membrane. Utilizing the ion depletion/enrichment process, ICP phenomenon has been applied in the vast field of inquiries on preconcentration of ionic molecules in the fluid. This study proposes an original capillary-based preconcentration device using Nafion, cation permselective membrane. The sample preconcentration could be easily achieved by utilizing the Nafion coated glass capillary. By applying the DC voltage to the developed preconcentration device, we observed that the charged fluorescent dye was successfully concentrated nearby the ion depletion zone. This observation would provide a platform of new preconcentration device owing to its simplified fabrication procedure compared to the previous devices.