title: Novel dense CO2 technique for beta-galactosidase immobilization in polystyrene microchannels.
abstract: In this study we design new fabrication techniques and demonstrate the potential of using dense CO2 for facilitating crucial steps in the fabrication of polymeric lab-on-a-chip microdevices by embedding biomolecules at temperatures well below the polymer's glass transition temperature (T(g)). These new techniques are environmentally friendly and done without the use of a clean room. Carbon dioxide at 40 degrees C and between 4.48 and 6.89 MPa was used to immobilize the biologically active molecule, beta-galactosidase (beta-gal), on the surface of polystyrene microchannels. To our knowledge, this is the first time dense CO2 has been used to directly immobilize an enzyme in a microchannel. beta-gal activity was maintained and shown via a fluorescent reaction product, after enzyme immobilization and microchannel capping by the designed fabrication steps at 40 degrees C and pressures up to 6.89 MPa.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Leclair Ellis
authors.forename: David L
authors.initials: DL
authors.lastname: Tomasko
authors.forename: Fariba
authors.initials: F
authors.lastname: Dehghani
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006801:Humans; D046208:Microchip Analytical Procedures; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature; D001616:beta-Galactosidase / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D011137:Polystyrenes; D002245:Carbon Dioxide; D001616:beta-Galactosidase