title: Electrochemical DNA probe for Hg(2+) detection based on a triple-helix DNA and Multistage Signal Amplification Strategy.
abstract: In this work, an ultrasensitive electrochemical sensor was developed for detection of Hg(2+). Gold nanoparticles decorated bovine serum albumin reduction of graphene oxide (AuNP-BSA-rGO) were used as subsurface material for the immobilization of triple-helix DNA. The triple-helix DNA containing a thiol labelled single-stranded DNA (sDNA) and a thymine-rich DNA (T-rich DNA), which could be unwinded in the present of Hg(2+) to form more stable thymine-Hg(2+)-thymine (T-Hg(2+)-T) complex. T-Hg(2+)-T complex was then removed and the sDNA was left on the electrode. At this time, gold nanoparticle carrying thiol labelled cytosine-rich complementary DNA (cDNA-AuNP) could bind with the free sDNA. Meanwhile, the other free cDNA on AuNP could bind with each other in the present of Ag(+) to form the stable cytosine-Ag(+)-cytosine (C-Ag(+)-C) complex and circle amplification. Plenty of C-Ag(+)-C could form silver nanoclusters by electrochemical reduction and the striping signal of Ag could be measured for purpose of the final electrochemical detection of Hg(2+). This sensor could detect Hg(2+) over a wide concentration range from 0.1 to 130nM with a detection limit of 0.03nM.
authors: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, PR China.
authors: Huan
authors: H
authors: Wang
authors: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, PR China. Electronic address: zyh@cugb.edu.cn.
authors: Yihe
authors: Y
authors: Zhang
authors: Key Laboratory of Chemical Sensing&Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Hongmin
authors: H
authors: Ma
authors: Key Laboratory of Chemical Sensing&Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Xiang
authors: X
authors: Ren
authors: Key Laboratory of Chemical Sensing&Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Yaoguang
authors: Y
authors: Wang
authors: Key Laboratory of Chemical Sensing&Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Yong
authors: Y
authors: Zhang
authors: Key Laboratory of Chemical Sensing&Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: sdjndxwq@163.com.
authors: Qin
authors: Q
authors: Wei
mesh_terms: D003217:Conductometry / Q000295:instrumentation*; D015342:DNA Probes / Q000737:chemistry* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008628:Mercury / Q000032:analysis*; D015336:Molecular Probe Techniques; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D015342:DNA Probes; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Cytosine–Ag(+)–cytosine complex; Hg(2+) detection; Multistage Signal Amplification Strategy; Thymine–Hg(2+)–thymine complex; Triple-helix DNA