title: The Ag+-G interaction inhibits the electrocatalytic oxidation of guanine--a novel mechanism for Ag+ detection.
abstract: The heavy metal ions-nucleobases interaction is an important research topic in environmental and biochemical analysis. The presence of the silver ion (Ag(+)) may influence the formation of oxidation intermediate and the electrocatalytic oxidation activity of guanine (G), since Ag(+) can interact with guanine at the binding sites which are involved in the electrocatalytic oxidation reaction of guanine. According to this principle, a new electrochemical sensor for indirectly detecting Ag(+) based on the interaction of Ag(+) with isolated guanine base using differential pulse voltammetry (DPV) was constructed. Among the heavy metal ions examined, only Ag(+) showed the strongest inhibitory effect on the electrocatalytic oxidation of guanine at the multi-walled carbon nanotubes modified glassy carbon electrode (CNTs/GC). And the quantitative study of Ag(+) based on Ag(+)-G sensing system gave a linear range from 100 nM to 2.5 μM with a detection limit of 30 nM. In addition, this modified electrode had very good reproducibility and stability. The developed electrochemical method is an ideal tool for Ag(+) detection with some merits including remarkable simplicity, low-cost, and no requirement for probe preparation.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering, Hunan University, Changsha, PR China.
authors.forename: Xingxing
authors.initials: X
authors.lastname: Liu
authors.forename: Wang
authors.initials: W
authors.lastname: Li
authors.forename: Qinpeng
authors.initials: Q
authors.lastname: Shen
authors.forename: Zhou
authors.initials: Z
authors.lastname: Nie
authors.forename: Manli
authors.initials: M
authors.lastname: Guo
authors.forename: Yitao
authors.initials: Y
authors.lastname: Han
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D000465:Algorithms; D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D002384:Catalysis; D055664:Electrochemical Techniques / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water / Q000032:analysis / Q000737:chemistry; D005898:Glass; D006147:Guanine / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012834:Silver / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D060986:Water Wells / Q000032:analysis / Q000737:chemistry
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D012834:Silver; D006147:Guanine