title: Electrochemical oligonucleotide-based biosensor for the determination of lead ion.
abstract: The possibility of utilization of gold electrodes modified with short guanine-rich ssDNA probes for determination of Pb(2+) was examined. Interaction between guanine residues and lead ion followed by formation of G-quadruplex structures was confirmed by electrochemical impedance spectroscopy investigations. An external cationic redox label, methylene blue, was employed in voltammetric measurements for analytical signal generation. It was shown that due to the G-quadruplex formation, the oligonucleotides in the recognition layer fold, which enhances the electron transfer between methylene blue and the electrode surface. The MB current signal rises proportionally to the lead ion concentration in the range from 0.05 to 1μmol/L. The developed biosensor demonstrated high selectivity towards Pb(2+) ion, with only minor response towards interfering metal cations. The calculated limit of detection was of 34.7nmol/L. The utilization of the biosensor for Pb(2+) determination in real samples of water was also tested.
authors.affiliation: Institute of Biotechnology, Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Jarczewska
authors.affiliation: Institute of Biotechnology, Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kierzkowska
authors.affiliation: Institute of Biotechnology, Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Ziółkowski
authors.affiliation: Institute of Biotechnology, Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. Electronic address: lukegor@ch.pw.edu.pl.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Górski
authors.affiliation: Institute of Biotechnology, Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Malinowska
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D002413:Cations, Divalent / Q000032:analysis; D004277:DNA, Single-Stranded / Q000737:chemistry; D058266:Dielectric Spectroscopy / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D008670:Metals / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D002413:Cations, Divalent; D004277:DNA, Single-Stranded; D061925:Immobilized Nucleic Acids; D008670:Metals; D009692:Nucleic Acid Heteroduplexes; D014874:Water Pollutants, Chemical; D014867:Water; D007854:Lead; D006046:Gold; D008751:Methylene Blue
keywords: DNA-based biosensors; Electrochemical sensors; Metal ion determination