Chem. J. Chinese Universities ›› 2010, Vol. 31 ›› Issue (6): 1131.

• Articles • Previous Articles     Next Articles

Fe3O4@Au Nanoparticles as Labels for Electrochemical Immunodetection of E.coli in Water

LIU Hui-Jie, TENG Ying-Qiao, ZHANG Xin-Ai, FU Ying, ZHANG Wen*, JIN Li-Tong   

  1. Department of Chemistry, East China Normal University, Shanghai 200062, China
  • Received:2009-11-25 Online:2010-06-10 Published:2010-06-10
  • Contact: ZHANG Wen. E-mail: wzhang@chem.ecnu.edu.cn
  • Supported by:

    国家自然科学基金(批准号: 20475017, 20775026)和上海市绿色化学与化工过程绿色化重点实验室开放基金资助.

Abstract:

Fe3O4@Au nanoparticles were synthesized in this paper. The surface of nanoparticles was modified with horseradish peroxidase(HRP)-anti-E.coli antibody for amplified electrochemical immunoassay of E.coli. Poly-thionine(PTH) film was electro-polymerized on the GCE as an electron-transfer mediator. Gold nanoparticles(GNPs) on the PTH film constructed an effective antibody immobilization matrix. Using the typical sandwich type immmunoassay, E.coli could be detected according to the H2O2 reduction currents catalyzed by HRP labeled on anti-E.coli antibody. The method allowed quantitative determination of E.coli concentration from 50 to 1×105 cfu/mL, with a detection limit of 20 cfu/mL. By introducing pre-enrichment steps, a concentration of 2 cfu/mL E.coli was detected with this method.

Key words: E.coli; Fe3O4@Au nanoparticle; Amplified immunoassay; Electrochemical immunoassay

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