Cascaded FRET in conjugated polymer/quantum dot/dye-labeled DNA complexes for DNA hybridization detection.
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.
Jiang
Guoxin
G
Ludwig-Maximilians-Universitat Munchen, Amalienstrasse 54, 80799 Munich, Germany.
Susha
Andrei S
AS
Lutich
Andrey A
AA
Stefani
Fernando D
FD
Feldmann
Jochen
J
Rogach
Andrey L
AL
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
D004247:DNA