title: Liposomes as signal amplification reagents for bioassays in microfluidic channels.
abstract: Liposomes with encapsulated carboxyfluorescein were used in an affinity-based assay to provide signal amplification for small-volume fluorescence measurements. Microfluidic channels were fabricated by imprinting in a plastic substrate material, poly(ethylene terephthalate glycol) (PETG), using a silicon template imprinting tool. Streptavidin was linked to the surface through biotinylated-protein for effective immobilization with minimal nonspecific adsorption of the liposome reagent. Lipids derivatized with biotin were incorporated into the liposome membrane to make the liposomes reactive for affinity assays. Specific binding of the liposomes to microchannel walls, dependence of binding on incubation time, and nonspecific adsorption of the liposome reagent were evaluated. The results of a competitive assay employing liposomes in the microchannels are presented.
authors.affiliation: Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8394, USA. laurie.locascio@nist.gov
authors.forename: Laurie E
authors.initials: LE
authors.lastname: Locascio
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Hong
authors.forename: Michael
authors.initials: M
authors.lastname: Gaitan
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods; D007202:Indicators and Reagents; D008081:Liposomes; D008832:Microchemistry / Q000379:methods*; D013862:Thiogalactosides
chemical_list: D007202:Indicators and Reagents; D008081:Liposomes; D013862:Thiogalactosides; C066907:phenylethylthio-beta-galactopyranoside