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Regenerable Leptin Immunosensor Based on Protein G Immobilized Au‐Pyrrole Propylic Acid‐Polypyrrole Nanocomposite
Author(s) -
Chen Wei,
Lei Yu,
Li Chang Ming
Publication year - 2010
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200900536
Subject(s) - detection limit , polypyrrole , immunoassay , chemistry , nanocomposite , covalent bond , nanoparticle , dielectric spectroscopy , chromatography , electrochemistry , electrode , nuclear chemistry , materials science , antibody , nanotechnology , organic chemistry , immunology , biology
A regenerable, labelless electrochemical immunosensor is investigated. In this work, pyrrole (Py) and pyrrole propylic acid (Pa) were co‐electropolymerized in the presence of gold nanoparticles to form a porous, conductive, stable and hydrophilic nanocomposite, followed by the covalent attachment of protein G to capture an antibody as the probe for the immunoassay. The regeneration of the sensor was achieved by rinsing the electrodes with 0.1 M glycine buffer (pH 2.7). The binding and dissociation of the antibody with protein G and optimization of the efficient immobilization were studied by impedance and optical measurements, respectively. The charge transfer resistance obtained from the impedance measurements is used to study the interaction between antibody‐protein G and antibody‐antigen. The immunosensor performance and its regenerability were evaluated by using anti‐leptin IgG as the probe protein to detect leptin in 0.01 M PBS, and its specificity was tested in 1% human serum. The leptin impedimetric immunosensor exhibits a detection dynamic range of 10–100 000 ng/mL with 10 ng/mL detection limit in 0.01 M PBS+1% serum solutions. This work proves the feasibility to make a sensitive, regenerative electrochemical immunosensor, which could be very useful for environmental control and food analysis.