title: Fluorescence resonance energy transfer in a binary organic nanoparticle system and its application.
abstract: Fluorescent organic nanoparticles have a much better photostability than molecule-based probes. Here, we report a simple strategy to detect chemicals and biomolecules by a binary nanoparticle system based on fluorescence resonance energy transfer (FRET). Poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO, energy donor) and poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV, energy acceptor) are utilized to prepare the binary nanoparticle system through a reprecipitation method. Since the FRET process is strongly distance-dependent, a change in the interparticle distance between the two kinds of nanoparticles after introduction of analytes will alter the FRET efficiency. The response of the binary nanoparticle system to cationic polyelectrolytes was investigated by monitoring the FRET efficiency from PFO to MEH-PPV nanoparticles and the fluorescence color of the nanoparticle solutions. Furthermore, the cationic polyelectrolyte pretreated binary nanoparticle system can be used to detect DNA by desorption of nanoparticles from the polyelectrolyte's chains and the detection concentration can go down to 10(-14) M. Thus, the binary nanoparticle system shows great promise for applications in chemical sensing or biosensing.
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wu
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
authors.forename: Xinjun
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
authors.forename: Jinshan
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
authors.forename: Lidong
authors.initials: L
authors.lastname: Li
mesh_terms: D002412:Cations; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D009930:Organic Chemicals / Q000737:chemistry*
chemical_list: D002412:Cations; D004573:Electrolytes; D009930:Organic Chemicals; D004247:DNA
keywords: conjugated polymer; fluorescence; fluorescence resonance energy transfer; organic nanoparticles; polyelectrolyte; reprecipitation