title: High yield sample preconcentration using a highly ion-conductive charge-selective polymer.
abstract: The development and analysis of a microfluidic sample preconcentration system using a highly ion-conductive charge-selective polymer [poly-AMPS (2-acrylamido-2-methyl-1-propanesulfonic acid)] is reported. The preconcentration is based on the phenomenon of concentration polarization which develops at the boundaries of the poly-AMPS with buffer solutions. A negatively charged polymer, poly-AMPS, positioned between two microchannels efficiently extracts cations through its large cross section, resulting in efficient anion sample preconcentration. The present work includes the development of a robust polymer that is stable over a wide range of buffers with varying chemical compositions. The sample preconcentration effect remains linear to over 3 mM (0.15 pmol) and 500 microM (15 fmol) for fluorescein and TRITC-tagged albumin solutions, respectively. The system can potentially be used for concentrating proteins on microfluidic devices with subsequent analysis for proteomic applications.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapman Hall, CB#3216, Chapel Hill, North Carolina 27599, USA.
authors.forename: Honggu
authors.initials: H
authors.lastname: Chun
authors.forename: Taek Dong
authors.initials: TD
authors.lastname: Chung
authors.forename: J Michael
authors.initials: JM
authors.lastname: Ramsey
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000476:Alkanesulfonates / Q000737:chemistry; D056656:Lab-On-A-Chip Devices; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D040901:Proteomics
chemical_list: D000178:Acrylamides; D000476:Alkanesulfonates; D011108:Polymers; C056288:2-acrylamido-2-methylpropanesulfonate