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Giant magnetoresistive biochip for DNA detection and HPV genotyping.

TitleGiant magnetoresistive biochip for DNA detection and HPV genotyping.
Publication TypeJournal Article
Year of Publication2008
AuthorsXu L, Yu H, Akhras MS, Han S-J, Osterfeld S, White RL, Pourmand N, Wang SX
JournalBiosens Bioelectron
Date Published2008 Sep 15
KeywordsBiosensing Techniques, DNA, Viral, Genotype, Magnetics, Oligonucleotide Array Sequence Analysis, Papillomaviridae, Sensitivity and Specificity

A giant magnetoresistive (GMR) biochip based on spin valve sensor array and magnetic nanoparticle labels was developed for inexpensive, sensitive and reliable DNA detection. The DNA targets detected in this experiment were PCR products amplified from Human Papillomavirus (HPV) plasmids. The concentrations of the target DNA after PCR were around 10 nM in most cases, but concentrations of 10 pM were also detectable, which is demonstrated by experiments with synthetic DNA samples. A mild but highly specific surface chemistry was used for probe oligonucleotide immobilization. Double modulation technique was used for signal detection in order to reduce the 1/f noise in the sensor. Twelve assays were performed with an accuracy of approximately 90%. Magnetic signals were consistent with particle coverage data measured with Scanning Electron Microscopy (SEM). More recent research on microfluidics showed the potential of reducing the assay time below one hour. This is the first demonstration of magnetic DNA detection using plasmid-derived samples. This study provides a direct proof that GMR sensors can be used for biomedical applications.

Alternate JournalBiosens Bioelectron
PubMed ID18457945
PubMed Central IDPMC2573902
Grant List1U54CA119367-01 / CA / NCI NIH HHS / United States
P01-HG000205 / HG / NHGRI NIH HHS / United States
U54 CA119367 / CA / NCI NIH HHS / United States
U54 CA119367-010001 / CA / NCI NIH HHS / United States