title: Luminescence stability improvement in liposome-based homogeneous luminescence resonance energy transfer.
abstract: A stable liposome-based time-resolved luminescence resonance energy transfer (TR-LRET) assay was developed based on the interaction of biotinylated lipids and streptavidin. Eu(3+) ion chelated to 4,4,4-trifluoro-1-(2-naphthalenyl)-1,3-butanedione and trioctylphosphine oxide was incorporated into liposomes. Acceptor-labeled streptavidin bound to biotinylated lipids of the liposomes enables TR-LRET. A stable assay performance was achieved by optimization. High Eu(3+) signal and stability, low variation, and sensitivity below 100 pM for free biotin was achieved by incorporating the chelate into liposomes containing cholesterol in a carbonate buffer. Potentially, the stable assay compared with the assay without cholesterol offers an improved platform to liposome-based detection systems.
authors.affiliation: Laboratory of Biophysics and Medicity Research Laboratory, University of Turku, 20520 Turku, Finland. sari.pihlasalo@utu.fi
authors.forename: Sari
authors.initials: S
authors.lastname: Pihlasalo
authors.forename: Jenny
authors.initials: J
authors.lastname: Granberg
authors.forename: Pekka
authors.initials: P
authors.lastname: Hänninen
authors.forename: Jouko
authors.initials: J
authors.lastname: Peltonen
authors.forename: Harri
authors.initials: H
authors.lastname: Härmä
mesh_terms: D001710:Biotin / Q000032:analysis / Q000737:chemistry*; D002784:Cholesterol / Q000032:analysis / Q000737:chemistry*; D005063:Europium / Q000032:analysis / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D007659:Ketones / Q000032:analysis / Q000737:chemistry*; D008081:Liposomes / Q000032:analysis / Q000737:chemistry*; D049449:Luminescence; D009281:Naphthalenes / Q000032:analysis / Q000737:chemistry*; D019809:Streptavidin / Q000032:analysis / Q000737:chemistry*
chemical_list: C534544:4,4,4-trifluoro-1-(2-naphthalenyl)-1,3-butanedione; D007659:Ketones; D008081:Liposomes; D009281:Naphthalenes; D005063:Europium; D001710:Biotin; D019809:Streptavidin; D002784:Cholesterol
keywords: Biotin; Cholesterol; Energy transfer; Liposome; Streptavidin; Time-resolved luminescence