title: Genomagnetic electrochemical assays of DNA hybridization.
abstract: An electrochemical genomagnetic hybridization assay has been developed to take advantage of a new and efficient magnetic separation/mixing process, the amplification feature of enzyme labels, and single-use thick-film carbon transducers operated in the pulse-voltammetric mode. It represents the first example of coupling a magnetic isolation with electrochemical detection of DNA hybridization. The new protocol employs an enzyme-linked sandwich solution hybridization, with a magnetic-particle labeled probe hybridizing to a biotinylated DNA target that captures a streptavidin-alkaline phosphatase (AP). The alpha-naphthol product of the enzymatic reaction is quantitated through its well-defined, low-potential (+0.1 V vs. Ag/AgCl) differential pulse-voltammetric peak at the disposable screen-printed electrode. The efficient magnetic isolation is particularly attractive for electrical detection of DNA hybridization which is commonly affected by the presence of non-hybridized nucleic acid adsorbates. The new biomagnetic processing combines such magnetic separation with a low-volume magnetic mixing, and allows simultaneous handling of 12 samples. The attractive bioanalytical behavior of the new enzyme-linked genomagnetic electrical assay is illustrated for the detection of DNA segments related to the breast-cancer BRCA1 gene.
authors.affiliation: Department of Chemistry and Biochemistry, College of Arts and Sciences, New Mexico State University, Las Cruces, NM 88003-8001, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang
authors.forename: Danke
authors.initials: D
authors.lastname: Xu
authors.forename: Arzum
authors.initials: A
authors.lastname: Erdem
authors.forename: Ronen
authors.initials: R
authors.lastname: Polsky
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Salazar