title: Out-of-equilibrium biomolecular interactions monitored by picosecond fluorescence in microfluidic droplets.
abstract: We developed a new experimental approach combining Time-Resolved Fluorescence (TRF) spectroscopy and Droplet Microfluidics (DμF) to investigate the relaxation dynamics of structurally heterogeneous biomolecular systems. Here DμF was used to produce with minimal material consumption an out-of-equilibrium, fluorescently labeled biomolecular complex by rapid mixing within the droplets. TRF detection was implemented with a streak camera to monitor the time evolution of the structural heterogeneity of the complex along its relaxation towards equilibrium while it propagates inside the microfluidic channel. The approach was validated by investigating the fluorescence decay kinetics of a model interacting system of bovine serum albumin and Patent Blue V. Fluorescence decay kinetics are acquired with very good signal-to-noise ratio and allow for global, multicomponent fluorescence decay analysis, evidencing heterogeneous structural relaxation over several 100 ms.
authors.affiliation: Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, Université de Strasbourg, CNRS UMR 7504, F-67034 Strasbourg Cedex 2, France. jeremie.leonard@ipcms.unistra.fr.
authors.forename: Sacha
authors.initials: S
authors.lastname: Maillot
authors.forename: Alain
authors.initials: A
authors.lastname: Carvalho
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Vola
authors.forename: Christian
authors.initials: C
authors.lastname: Boudier
authors.forename: Yves
authors.initials: Y
authors.lastname: Mély
authors.forename: Stefan
authors.initials: S
authors.lastname: Haacke
authors.forename: Jérémie
authors.initials: J
authors.lastname: Léonard
mesh_terms: D000818:Animals; D002417:Cattle; D005456:Fluorescent Dyes / Q000737:chemistry*; D007700:Kinetics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D009821:Oils / Q000737:chemistry; D012394:Rosaniline Dyes / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism; D059629:Signal-To-Noise Ratio; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D009821:Oils; D012394:Rosaniline Dyes; D014867:Water; D012710:Serum Albumin, Bovine; C008769:sulfan blue