Electrochemical impedance characterization of antibody-antigen interaction with signal amplification based on polypyrrole-streptavidin.
Streptavidin, as a dopant, has been incorporated into a polypyrrole film to bind biotinylated antibody onto the electrode surface. With four biotin binding sites, the incorporation of streptavdin, as confirmed by FTIR and impedance spectroscopy, provided a new method to amplify the response signal from antibody-antigen interaction. Biotinylated anti-goat IgG, as a probe, and goat IgG, as a target, were employed to evaluate the characteristics of the biosensor. With the amplification strategy, the detection sensitivity of the electrochemical impedance spectroscopy was significantly improved. A linear relationship between the charge transfer resistance change (DeltaR(t)) and the concentration of goat IgG ranging from 10 pg/ml to 100 ng/ml was obtained.
Xiao
Yinghong
Y
School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457, Singapore.
Li
Chang Ming
CM
Liu
Yingshuai
Y
D000937:Antigen-Antibody Reactions; D015374:Biosensing Techniques / Q000379:methods*; D019921:Biotinylation; D017097:Electric Impedance; D004563:Electrochemistry / Q000379:methods*; D007074:Immunoglobulin G / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry*
D007074:Immunoglobulin G; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D019809:Streptavidin