title: Measurement of electroosmotic flow in plastic imprinted microfluid devices and the effect of protein adsorption on flow rate.
abstract: Several commercially available plastic materials were used as substrates in the fabrication of microfluid channels for biochemical analysis. Protocols for fabrication using the wire-imprinting method are reported for polystyrene, polymethylmethacrylate and a copolyester material. Channel sealing was accomplished by low-temperature bonding of a substrate of similar material; therefore, each channel was composed of a single material on all sides. The electroosmotic flow in 25-microm imprinted channels was evaluated for each substrate material. The copolyester material exhibited the highest electroosmotic flow mobility of 4.3 x 10(-4) cm2 V(-1) s(-1) which is similar to that previously reported for fused-silica capillaries. Polystyrene exhibited the lowest electroosmotic flow mobility of 1.8 x 10(-4) cm2 V(-1) s(-1). Plots of linear velocity versus applied electric field strength were linear from 100 V cm(-1) to 500 V cm(-1) indicating that heat dissipation is effective for all substrates in this range. Electroosmotic flow was reevaluated in the plastic channels following incubation in antibody solution to access the non-specific binding characteristics of a common biochemical reagent onto the substrate materials. All materials tested showed a high degree of non-specific adsorption of IgG as indicated by a decrease in the electroosmotic flow mobility in post-incubation testing.
authors.affiliation: Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. laurie.locascio@nist.gov
authors.forename: L E
authors.initials: LE
authors.lastname: Locascio
authors.forename: C E
authors.initials: CE
authors.lastname: Perso
authors.forename: C S
authors.initials: CS
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D000906:Antibodies / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D009995:Osmosis
chemical_list: D000906:Antibodies