Luminescence stability improvement in liposome-based homogeneous luminescence resonance energy transfer.

Sari Pihlasalo, Jenny Granberg, Pekka Hänninen, Jouko Peltonen, Harri Härmä

Index: Anal. Biochem. 440(1) , 6-8, (2013)

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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.Copyright © 2013 Elsevier Inc. All rights reserved.