[Analytical Chemistry] Faradaic Ion Concentration Polarization on a Paper Fluidic Platform
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.
Xiang Li, Long Luo, and Richard M. Crooks*
Department of Chemistry, The University of Texas at Austin, 105 East 24th Street Stop A5300, Austin, Texas 78712-1224 United States
Anal. Chem., Article ASAP
Publication Date (Web): March 17, 2017
Copyright © 2017 American Chemical Society
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