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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/7785

Title: Towards a real-time, label-free, diamond-based DNA sensorle
Authors: VERMEEREN, Veronique
BIJNENS, Nathalie
DAENEN, Michael
VAN DE VEN, Martin
WAGNER, Patrick
Issue Date: 2007
Citation: LANGMUIR, 23(26). p. 13193-13202
Abstract: Most challenging in the development of DNA sensors is the ability to distinguish between fully complementary target ssDNA (single-strand DNA) and 1-mismatch ssDNA. To deal with this problem, we performed impedance spectroscopy on DNA-functionalized nanocrystalline diamond (NCD) layers during hybridization and denaturation. In both reactions, a difference in behavior was observed for 1-mismatch target DNA and complementary target DNA in real-time. During real-time hybridization, a decrease of the impedance was observed at lower frequencies when the complementary target DNA was added, while the addition of 1-mismatch target ssDNA caused no significant change. Fitting these results to an electrical circuit demonstrates that this is correlated with a decrease of the depletion zone in the space charge region of the diamond. During real-time denaturation, differentiation between 1-mismatch and complementary target DNA was possible at higher frequencies. Denaturation of complementary DNA showed the longest exponential decay time of the impedance, while the decay time during 1-mismatch denaturation was the shortest. The real-time hybridization and denaturation experiments were carried out on different NCD samples in various buffer solutions at temperatures between 20 and 80 degrees C. It was revealed that the best results were obtained using a Microhyb hybridization buffer at 80 degrees C and 10 x PCR buffer at 30 degrees C for hybridization and 0.1 M NaOH at temperatures above 40 degrees C for denaturation. We demonstrate that the combination of real-time hybridization spectra and real-time denaturation spectra yield important information on the type of target. This approach may allow a reliable identification of the mismatch sequence, which is the most biologically relevant.
Notes: Hasselt Univ & Transnatl Univ Limburg, Sch Life Sci, Biomed Res Inst, B-3590 Diepenbeek, Belgium. Hasselt Univ & Transnatl Univ Limburg, Sch Life Sci, Inst Mat Res, B-3590 Diepenbeek, Belgium. IMEC, Div IMOMEC, B-3590 Diepenbeek, Belgium.Michiels, L, Hasselt Univ & Transnatl Univ Limburg, Sch Life Sci, Biomed Res Inst, Agoralaan,Bldg A, B-3590 Diepenbeek, Belgium.luc.michiels@uhasselt.be
URI: http://hdl.handle.net/1942/7785
DOI: 10.1021/la702143d
ISI #: 000251583000058
ISSN: 0743-7463
Category: A1
Type: Journal Contribution
Validation: ecoom, 2009
Appears in Collections: Research publications

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