title: Detection of hepatitis B virus DNA with a paper electrochemical sensor.
abstract: Here we show that a simple paper-based electrochemical sensor, fabricated by paper folding, is able to detect a 30-base nucleotide sequence characteristic of DNA from the hepatitis B virus (HBV) with a detection limit of 85 pM. This device is based on design principles we have reported previously for detecting proteins via a metalloimmunoassay. It has four desirable attributes. First, its design combines simple origami (paper folding) assembly, the open structure of a hollow-channel paper analytical device to accommodate micrometer-scale particles, and a convenient slip layer for timing incubation steps. Second, two stages of amplification are achieved: silver nanoparticle labels provide a maximum amplification factor of 250 000 and magnetic microbeads, which are mobile solid-phase supports for the capture probes, are concentrated at a detection electrode and provide an additional ∼25-fold amplification. Third, there are no enzymes or antibodies used in the assay, thereby increasing its speed, stability, and robustness. Fourth, only a single sample incubation step is required before detection is initiated.
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
authors.forename: Karen
authors.initials: K
authors.lastname: Scida
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Crooks
mesh_terms: D004279:DNA, Viral / Q000032:analysis*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D006515:Hepatitis B virus / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D010209:Paper; D012834:Silver / Q000737:chemistry
chemical_list: D004279:DNA, Viral; D012834:Silver