title: An electrochemical biosensor for ultratrace terbium based on Tb3+ promoted conformational change of human telomeric G-quadruplex.
abstract: A new electrochemical biosensor for the monitoring of ultratrace terbium based on the conformational change of DNA containing a single guanine (G)-rich stretch was described here. The biosensor was fabricated by immobilizing a thiolated DNA containing a single G-rich stretch on the gold surface as probe surface. The G-rich DNA probe was found to be capable of changing its configuration from flexible single-stranded structures to rigid tetramolecular G-quadruplex in the presence of terbium III, which provided a switchable charge transport path for the oxidation of [Fe(CN)(6)](4-). The switchable surface provided a sensing platform for the single-step and reagentless detection of Tb(3+). Using this reusable electrochemical sensing platform, a simple, rapid, and selective biosensor for the determination of ultratrace terbium ions with a detection limit of 6.0 x 10(-11)M has been developed. The success in the present biosensor served as a significant step toward the development of monitoring ultratrace Tb(3+) in river water or seawater.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, and Department of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Jinghua
authors.initials: J
authors.lastname: Chen
authors.forename: Rongchun
authors.initials: R
authors.lastname: Chen
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
authors.forename: Fengfu
authors.initials: F
authors.lastname: Fu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054856:G-Quadruplexes; D006801:Humans; D008832:Microchemistry / Q000295:instrumentation*; D009690:Nucleic Acid Conformation; D016615:Telomere / Q000737:chemistry* / Q000235:genetics; D013725:Terbium / Q000032:analysis* / Q000737:chemistry*
chemical_list: D013725:Terbium