title: Sensitive quantitative protein concentration method using luminescent resonance energy transfer on a layer-by-layer europium(III) chelate particle sensor.
abstract: A particle-based protein quantification method was developed. The method relies on adsorption of proteins on particles and time-resolved fluorescence resonance energy transfer (TR-FRET). Layer-by-layer (LbL) particles containing europium(III) chelate donor were prepared. A protein labeled with an acceptor was adsorbed onto the particles and near-infrared energy transfer signal was detected in time-gated detection mode. Sample proteins efficiently occupied the particle surface preventing binding of the acceptor-labeled protein leading to a particle sensor with a significant signal change. We detected subnanomolar protein concentration using the rapid and simple mix-and-measure method with a coefficient of variation below 10%. Compared to known protein concentration methods, the developed method required no hazardous substances or elevated temperature to reach the high-sensitivity level.
authors.affiliation: Laboratory of Biophysics and Medicity, University of Turku, FIN-20520 Turku, Finland. harri.harma@utu.fi
authors.forename: Harri
authors.initials: H
authors.lastname: Härmä
authors.forename: Lars
authors.initials: L
authors.lastname: Dähne
authors.forename: Sari
authors.initials: S
authors.lastname: Pihlasalo
authors.forename: Janne
authors.initials: J
authors.lastname: Suojanen
authors.forename: Jouko
authors.initials: J
authors.lastname: Peltonen
authors.forename: Pekka
authors.initials: P
authors.lastname: Hänninen
mesh_terms: D015374:Biosensing Techniques; D002614:Chelating Agents / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D005063:Europium / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D053768:Metal Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000032:analysis* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D011506:Proteins; D012710:Serum Albumin, Bovine; D005063:Europium