Capillary-valve-based fabrication of ion-selective membrane junction for electrokinetic sample preconcentration in PDMS chip
Author(s)Liu, Vincent Hok; Song, Yong-Ak; Han, Jongyoon
MetadataShow full item record
In this paper, we report a novel method for fabricating ion-selective membranes in poly(dimethylsiloxane) (PDMS)/glass-based microfluidic preconcentrators. Based on the concept of capillary valves, this fabrication method involves filling a lithographically patterned junction between two microchannels with an ion-selective material such as Nafion resin; subsequent curing results in a high aspect-ratio membrane for use in electrokinetic sample preconcentration. To demonstrate the concentration performance of this high-aspect-ratio, ion-selective membrane, we integrated the preconcentrator with a surface-based immunoassay for R-Phycoerythrin (RPE). Using a 1× PBS buffer system, the preconcentrator-enhanced immunoassay showed an approximately 100× improvement in sensitivity within 30 min. This is the first time that an electrokinetic microfluidic preconcentrator based on ion concentration polarization (ICP) has been used in high ionic strength buffer solutions to enhance the sensitivity of a surface-based immunoassay.
DepartmentMassachusetts Institute of Technology. Department of Biological Engineering; Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Lab on a Chip
Royal Society of Chemistry (RSC Publishing)
Liu, Vincent, Yong-Ak Song, and Jongyoon Han. “Capillary-valve-based Fabrication of Ion-selective Membrane Junction for Electrokinetic Sample Preconcentration in PDMS Chip.” Lab on a Chip 10.11 (2010): 1485.
Author's final manuscript