A high sensitive label-free immunosensor for the determination of human serum IgG using overoxidized polypyrrole decorated with gold nanoparticle modified electrode

Herein, an electrochemical human immunoglobulin G (HIgG) immunosensor was fabricated using overoxidized polypyrrole decorated with gold nanoparticle (OPPy-Au-nano) modified screen printed electrode (OPPy-Au-nano/SPE). The results clearly demonstrate that OPPy-Au-nano film is very permeable to [Fe(CN)(6)](3-/4-). Therefore, the fabrication of immunosensor based on permeability of OPPy-Au-nano film to [Fe(CN)(6)](3-/4-) probe is a novel strategy for the fabrication of label free electrochemical immunosensor. The electrochemical impedance spectroscopy (EIS) techniques are used for the determination of HIgG in the concentration range 0.5 to 125.0 ng ml(-1) and with a limit of detection of 0.02 ng mL(-1), respectively. (C) 2015 Elsevier B.V. All rights reserved.