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A novel reagentless amperometric immunosensor based on gold nanoparticles/TMB/Nafion-modified electrode

2008; Elsevier BV; Volume: 24; Issue: 5 Linguagem: Inglês

10.1016/j.bios.2008.07.075

1873-4235

Ying Wu, Junwei Zheng, Zheng Li, Yanrong Zhao, Yu Zhang,

Electrochemical sensors and biosensors

A novel reagentless immunosensor was fabricated by immobilization of redox mediator 3,3′,5,5′-tetramethylbenzidine (TMB) on the Nafion (Nf) film modified glassy carbon electrode. Gold nanoparticles were assembled onto the TMB/Nafion film modified electrode to provide active sites for the immobilization of antibody molecules. The antibody (anti-MIgG), in the present study, was fixed on the electrode for the rapid detection of antigen molecules (MIgG as a model analyte). The results showed that the immunosensor based on the immobilized TMB redox mediator exhibited good electrochemical response. A good linear relationship between peak current and the concentration of the MIgG was obtained in the concentration range from 4 to 120 ng/mL. The detection limit was estimated to be 1 ng/ml. Under the optimized conditions, the immunosensor exhibits good sensitivity, reproducibility and stability.