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

作者：Liu Hui-Jie; Teng Ying-Qiao; Zhang Xin-Ai; Fu Ying; Zhang Wen^*; Jin Li-Tong

来源：Chemical Journal of Chinese Universities, 2010, 31(6): 1131-1136.

• E. coli
• Fe3O4 @ Au nanoparticle
• Amplified immunoassay
• Electrochemcial immunoassay

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-tansfer 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 x 10(5) 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.

• 出版日期2010-6-10
• 单位华东师范大学