Pingping Wang

Nanchang University, Nan-ch’ang-shih, Jiangxi Sheng, China

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Publications (3)15.03 Total impact

  • Yongnian Ni · Pingping Wang · Haiyan Song · Xiaoyun Lin · Serge Kokot
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    ABSTRACT: A novel electrochemical biosensor, DNA/hemin/nafion-graphene/GCE, was constructed for the analysis of the benzo(a)pyrene PAH, which can produce DNA damage induced by a benzo(a)pyrene (BaP) enzyme-catalytic product. This biosensor was assembled layer-by-layer, and was characterized with the use of cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and atomic force microscopy. Ultimately, it was demonstrated that the hemin/nafion-graphene/GCE was a viable platform for the immobilization of DNA. This DNA biosensor was treated separately in benzo(a)pyrene, hydrogen peroxide (H2O2) and in their mixture, respectively, and differential pulse voltammetry (DPV) analysis showed that an oxidation peak was apparent after the electrode was immersed in H2O2. Such experiments indicated that in the presence of H2O2, hemin could mimic cytochrome P450 to metabolize benzo(a)pyrene, and a voltammogram of its metabolite was recorded. The DNA damage induced by this metabolite was also detected by electrochemical impedance and ultraviolet spectroscopy. Finally, a novel, indirect DPV analytical method for BaP in aqueous solution was developed based on the linear metabolite versus BaP concentration plot; this method provided a new, indirect, quantitative estimate of DNA damage.
    No preview · Article · Apr 2014 · Analytica chimica acta
  • Pingping Wang · Yongnian Ni · Serge Kokot
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    ABSTRACT: A novel biosensor consisting of a glassy carbon electrode (GCE) modified by a polydiphenylamine-4-sulfonic acid (PDPASA, conjugated polymer) film and double-stranded DNA (dsDNA), i.e. dsDNA/PDPASA/GCE, was researched and developed for the analysis of catechol - a potentially toxic substance for humans and the environment. The surface properties of the PDPASA film, particularly after dsDNA was immobilized on it, were characterized with the use of atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The surfaces of the novel DNA/PDPASA/GCE biosensor changed during the fabrication process and displayed high sensitivity for catechol. The oxidation potential of catechol decreased significantly and the corresponding current increased substantially as compared with the values obtained at the GCE alone and at the dsDNA/GCE. Also, with the addition of hydroquinone, two well discriminated CV peaks were obtained, and it was demonstrated that hydroquinone did not interfere with catechol. DPV analysis produced a linear catechol calibration (range: 0.750 to 8.25 × 10(-6) mol L(-1); detection limit: 6.48 × 10(-7) mol L(-1)), and thus, various water samples were analysed successfully by this novel method. In addition, the DNA/PDPASA/GCE was used to study DNA damage in the presence of catechol with the use of the Co(phen)(3)(3+) electroactive probe. Results indicated that the potentially toxic catechol and its metabolites were all responsible for DNA damage.
    No preview · Article · Dec 2012 · The Analyst
  • Yongnian Ni · Pingping Wang · Serge Kokot
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    ABSTRACT: Electrochemical behavior of nitrofurazone (NFZ) was investigated with the use of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The pH-dependence of NFZ was studied at a glassy carbon electrode (GCE) in ethanol/Britton-Robinson buffer (30:70), and short-lived nitro-radicals were generated by the reduction of NFZ at high pHs (>7.0). In the presence of DNA, the DPV peak current of NFZ decreased and the peak potential shifted negatively, which indicated that there was an electrostatic interaction between NFZ and DNA. An electrochemical dsDNA/GCE biosensor was prepared to study the DNA damage produced in the presence NFZ; this process was followed with the use of the Co(phen)(3)(2+) electroactive probe. Also, the oxidation peaks of guanosine (750 mV) and adenosine (980 mV) indicated that DNA damage was related directly to the nitro-radicals. Experiments demonstrated that DNA damage occurred via two different steps while NFZ was metabolized and nitro-radicals were produced. Novel work with AFM on the NFZ/DNA interaction supported the suggestion that in vivo, the nitro-radicals were more cytotoxic than the NFZ molecules. A linear DPV calibration plot was obtained for NFZ analysis at a modified dsDNA/GCE (concentration range: 2.50 × 10(-6)-3.75 × 10(-5) mol L(-1); limit of detection: 8.0 × 10(-7) mol L(-1)), and NFZ was determined successfully in pharmaceutical samples.
    No preview · Article · Jun 2012 · Biosensors & Bioelectronics