title: Faradaic Ion Concentration Polarization on a Paper Fluidic Platform.
abstract: We describe the design and characteristics of a paper-based analytical device for analyte concentration enrichment. The device, called a hybrid paper-based analytical device (hyPAD), uses faradaic electrochemistry to create an ion depletion zone (IDZ), and hence a local electric field, within a nitrocellulose flow channel. Charged analytes are concentrated near the IDZ when their electrophoretic and electroosmotic velocities balance. This process is called faradaic ion concentration polarization. The hyPAD is simple to construct and uses only low-cost materials. The hyPAD can be tuned for optimal performance by adjusting the applied voltage or changing the electrode design. Moreover, the throughput of hyPAD is 2 orders of magnitude higher than that of conventional, micron-scale microfluidic devices. The hyPAD is able to concentrate a range of analytes, including small molecules, DNA, proteins, and nanoparticles, in the range of 200-500-fold within 5 min.
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street Stop A5300, Austin, Texas 78712-1224 United States.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street Stop A5300, Austin, Texas 78712-1224 United States.
authors.forename: Long
authors.initials: L
authors.lastname: Luo
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street Stop A5300, Austin, Texas 78712-1224 United States.
authors.forename: Richard M
authors.identifier: 0000-0001-5186-4878
authors.initials: RM
authors.lastname: Crooks
mesh_terms: D015374:Biosensing Techniques; D001896:Boron Compounds / Q000032:analysis*; D004247:DNA / Q000032:analysis; D055664:Electrochemical Techniques; D004566:Electrodes; D005456:Fluorescent Dyes / Q000032:analysis*; D007477:Ions / Q000032:analysis; D046210:Microfluidic Analytical Techniques; D053758:Nanoparticles / Q000032:analysis; D010209:Paper; D010316:Particle Size; D011506:Proteins / Q000032:analysis; D013499:Surface Properties
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D005456:Fluorescent Dyes; D007477:Ions; D011506:Proteins; D004247:DNA