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Journal of Electrochemistry ›› 2015, Vol. 21 ›› Issue (1): 22-28.doi: 10.13208/j.electrochem.140442

• Special Issue of Bioelectroanalyical Chemistry (Editor: Professor XIA Xing-hua, Nanjing University) • Previous Articles     Next Articles

Sensitive Detection of Hydroxyl Radical based on Silver-Enhanced Gold Nanoparticle Label

YANG Yan1,2, YU Peng1, ZHANG Xiao-hua1,*, CHEN Jin-hua1,*   

  1. 1. State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha Hunan 410082, China; 2. College of Chemistry and Pharmaceutical engineering, Nanyang Normal University, Henan Nanyang, 473061, China
  • Received:2014-08-04 Revised:2014-09-25 Online:2015-02-28 Published:2014-09-30
  • Contact: CHEN Jin-hua, ZHANG Xiao-hua E-mail:chenjinhua@hnu.edu.cn; mickyxie@hnu.edu.cn

Abstract: A novel DNA-based electrochemical sensor has been successfully constructed for sensitive detection of hydroxyl radical (·OH) based on the silver-enhanced gold nanoparticle label. Thiolated DNA1 was firstly immobilized on the gold electrode through Au—S bonds. The ·OH generated from Fenton reaction could induce serious oxidative damage of the DNA1 layer on the electrode surface. Then DNA2-functionalized gold nanoparticles (DNA2-AuNPs) were linked on the electrode through the hybridization between DNA2 and undamaged DNA1. Based on the catalytic reduction of silver ion by AuNPs, a silver layer was formed on the surface of AuNPs. The quantitative assay of ·OH was carried out by differential pulse voltammetry (DPV) detection of the deposited silver. Under the optimization conditions, the developed DNA-based biosensor could detect ·OH quantitatively with wide linear range (0.2 ~ 200 μmol·L-1) and low detection limit (50 nmol·L-1), and exhibited satisfactory selectivity and reproducibility. This electrochemical biosensor could have potential application in the evaluation of antioxidant capacity.

Key words: hydroxyl radical, DNA damage, gold nanoparticle, silver-enhancement, electrochemical sensor

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