Comparative Studies on Conducting Polymers for Immunosensor Applications

Electrochemical, structural and morphological studies were performed on polyaniline and polypyrrole films prepared in Sodium Dodecyl Sulfate (SDS) aqueous solutions for biosensor applications. For this purpose, impedance spectroscopy and atomic force microscopy (AFM) were successively applied. Based on neutravidin entrapment inside the electrogenerated polymers followed by specific Fab fragment-antibody grafting, atrazine immunosensor was developed. The impedance measurements with polyaniline and polypyrrole polymers reveal that immunosensor could detect significantly 0.01 ng/ml and 0.1 ng/ml atrazine respectively. This lower limit detection is due to the morphological structure of the polymers and especially to their porosity. For unspecific detection, no significant response was recorded after injection of different concentrations of rabbit IgG.