AVS 51st International Symposium
    Biomaterial Interfaces Friday Sessions
       Session BI+MN-FrM

Paper BI+MN-FrM7
Polymeric Materials for DNA Sensing and Integration into Microfluidic Channels

Friday, November 19, 2004, 10:20 am, Room 210D

Session: Bio-MEMS and Microfluidics
Presenter: R.A. Zangmeister, National Institute of Standards and Technology
Authors: R.A. Zangmeister, National Institute of Standards and Technology
M.J. Tarlov, National Institute of Standards and Technology
Correspondent: Click to Email
Advances in microchip technology coupled with innovative bioassays are advancing the field of biosensing in microfluidics. We have previously reported a method for immobilizing single-stranded DNA (ss-DNA) probe molecules in polyacrylamide hydrogels within plastic microfluidic channels, creating a sensing matrix for target oligos. Spatially defined plugs are formed by photopolymerization of a solution containing 19:1 polyacrylamide/bisacrylamide and ss-DNA modified at the 5' end with an acrylic acid group. Low concentrations of ss-DNA targets can be electrophoresed into the hydrogels where complementary strands are captured by hybridization and are detected. We are interested in identifying and characterizing other polymeric materials that can be used as DNA sensing matrices for use in microchannel devices. Our goal is to identify polymeric materials that can be patterned within a microchannel, either by photochemical or electrochemical means, and that possess surface chemical groups that can be used to chemically graft probe oligos, or potentially other biological probe molecules, onto the surface. One such candidate that we are currently investigating is poly(3-aminophenol). Our strategy is to pattern a poly(3-aminophenol) thin film, modify it with probe oligos, and demonstrate a hybridization based DNA assay on that surface for use in a microfluidic format. We are able to selectively deposit poly(3-aminophenol) thin films onto gold electrodes under potential control. Surface pendant amine groups, as evidenced in infrared studies, allow for linkage of probe oligos to the polymer surface. Polymer deposition conditions, characterization, modification with probe oligos, and success of target hybridization detection will be discussed.