The Ag+-G interaction inhibits the electrocatalytic oxidation of guanine--a novel mechanism for Ag+ detection |
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Authors: | Liu Xingxing Li Wang Shen Qinpeng Nie Zhou Guo Manli Han Yitao Liu Wei Yao Shouzhuo |
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Institution: | State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China |
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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. |
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Keywords: | Silver ion Guanine Inhibition Electrocatalytic oxidation Carbon nanotubes |
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