title: A novel electrochemical biosensor based on dynamic polymerase-extending hybridization for E. coli O157:H7 DNA detection.
abstract: A novel biosensor based on single-stranded DNA (ssDNA) probe functionalized aluminum anodized oxide (AAO) nanopore membranes was demonstrated for Escherichia coli O157:H7 DNA detection. An original and dynamic polymerase-extending (PE) DNA hybridization procedure is proposed, where hybridization happens in the existence of Taq DNA polymerase and dNTPs under controlled reaction temperature. The probe strand would be extended as long as the target DNA strand, then the capability to block the ionic flow in the pores has been prominently enhanced by the double strand complex. We have investigated the variation of ionic conductivity during the fabrication of the film and the hybridization using cyclic voltammetry and impedance spectroscopy. The present approach provides low detection limit for DNA (a few hundreds of pmol), rapid label-free and easy-to-use bacteria detection, which holds the potential for future use in various ss-DNA analyses by integrated into a self-contained biochip.
authors.affiliation: Zhejiang California International Nanosystems Institute, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Lijiang
authors.initials: L
authors.lastname: Wang
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Liu
authors.forename: Zhaoying
authors.initials: Z
authors.lastname: Hu
authors.forename: Yuanfan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Wu
authors.forename: Mo
authors.initials: M
authors.lastname: Yang
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000032:analysis*; D004563:Electrochemistry / Q000379:methods; D019453:Escherichia coli O157 / Q000235:genetics*; D009693:Nucleic Acid Hybridization
chemical_list: D004277:DNA, Single-Stranded