title: Cascaded FRET in conjugated polymer/quantum dot/dye-labeled DNA complexes for DNA hybridization detection.
abstract: Electrostatic complexes of a water-soluble fluorescent conjugated polymer, poly[9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)propyl)-2,7-fluorene-alt-1,4-phenylene]dibromide (PDFD), and water-soluble CdTe quantum dots (QDs) are designed to provide a cascaded FRET for DNA hybridization detection. PDFD has two functions in the detection scheme: as a light-harvesting antenna, it enhances the emission of QDs by the first level FRET and inverts the sign of the surface charge of QDs, thus providing a positively charged surface to allow negatively charged dye-labeled DNA to interact with the resulting complex. This interaction causes the second level FRET to infrared-emitting dye labeled on the probe DNA, providing a reliable signal-on sensing platform discriminating between complementary and non-complementary DNA. A detailed spectroscopic study offers a clear description of photophysical processes in the designed polymer/QD/DNA complex, providing ample potential for further sensitivity and selectivity improvements.
authors.affiliation: Ludwig-Maximilians-Universitat Munchen, Amalienstrasse 54, 80799 Munich, Germany.
authors.forename: Guoxin
authors.initials: G
authors.lastname: Jiang
authors.forename: Andrei S
authors.initials: AS
authors.lastname: Susha
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Lutich
authors.forename: Fernando D
authors.initials: FD
authors.lastname: Stefani
authors.forename: Jochen
authors.initials: J
authors.lastname: Feldmann
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Rogach
mesh_terms: D004247:DNA / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation* / Q000379:methods; D017404:In Situ Hybridization, Fluorescence / Q000295:instrumentation* / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D045663:Quantum Dots; D013194:Staining and Labeling
chemical_list: D004247:DNA