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Denaturation strategies for detection of double stranded PCR products on GMR magnetic biosensor array.

TitleDenaturation strategies for detection of double stranded PCR products on GMR magnetic biosensor array.
Publication TypeJournal Article
Year of Publication2016
AuthorsRizzi G, Lee J-R, Guldberg P, Dufva M, Wang SX, Hansen MF
JournalBiosens Bioelectron
Date Published2016 Sep 12
ISSN1873-4235
Abstract

Microarrays and other surface-based nucleic acid detection schemes rely on the hybridization of the target to surface-bound detection probes. We present the first comparison of two strategies to detect DNA using a giant magnetoresistive (GMR) biosensor platform starting from an initially double-stranded DNA target. The target strand of interest is biotinylated and detected by the GMR sensor by linking streptavidin magnetic nanoparticles (MNPs) to the sensor surface. The sensor platform has a dynamic detection range from 40pM to 40nM with highly reproducible results and is used to monitor real-time binding signals. The first strategy, using off-chip heat denaturation followed by sequential on-chip incubation of the nucleic acids and MNPs, produces a signal that stabilizes quickly but the signal magnitude is reduced due to competitive rehybridization of the target in solution. The second strategy, using magnetic capture of the double-stranded product followed by denaturing, produces a higher signal but the signal increase is limited by diffusion of the MNPs. Our results show that both strategies give highly reproducible results but that the signal obtained using magnetic capture is higher and insensitive to rehybridization.

DOI10.1016/j.bios.2016.09.031
Alternate JournalBiosens Bioelectron
PubMed ID27650710