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Dokumenttyp:
Zeitschriftenaufsatz 
Autor(en):
Rant, U.; Arinaga, K.; Scherer, S.; Pringsheim, E.; Fujita, S.; Yokoyama, N.; Tornow, M.; Abstreiter, G. 
Titel:
Switchable DNA interfaces for the highly sensitive detection of label-free DNA targets 
Abstract:
We report a method to detect label-free oligonucleotide targets. The conformation of surface-tethered probe nucleic acids is modulated by alternating electric fields, which cause the molecules to extend away from or fold onto the biased surface. Binding (hybridization) of targets to the single-stranded probes results in a pronounced enhancement of the layer-height modulation amplitude, monitored optically in real time. The method features an exceptional detection limit of <3 × 108 bound targets per cm2 sensor area. Single base-pair mismatches in the sequences of DNA complements may readily be identified; moreover, binding kinetics and binding affinities can be determined with high accuracy. When driving the DNA to oscillate at frequencies in the kHz regime, distinct switching kinetics are revealed for single- and double-stranded DNA. Molecular dynamics are used to identify the binding state of molecules according to their characteristic kinetic fingerprints by using a chip-compatible detection format. 
Stichworte:
fluorescence sensor SNP affinity energy transfer 
Zeitschriftentitel:
PNAS vol. 104 no. 44 17364–17369 2007-10 
Jahr:
2007 
Jahr / Monat:
2007-10 
Quartal:
4. Quartal 
Monat:
Oct 
Seitenangaben Beitrag:
17364-17369 
Reviewed:
ja 
Sprache:
en 
Verlag / Institution:
PNAS Proceedings of the National Academy of Sciences of the United States of America