Application of Polyaniline to an Enzyme-Amplified Electrochemical Immunosensor as an Electroactive Report Molecule

Conducting polymers (CPs) are widely used as matrixes for the entrapment of enzymes in analytical chemistry and biosensing devices However, enzyme-catalyzed polymerization of CPs is rarely used for immunosensing due to the difficulties involved in the quantitative analysis of colloidal CPs in solution phase In this study, an enzyme-amplified electrocatalytic immunosensor employing a CP as a redox marker has been developed A polyanionic polymer matrix, alpha-amino-omega-thiol terminated poly(acrylic acid), was employed for precipitation of CP The acrylic acid group acts as a polyanionic template The thiol terminus of the polymer was used to produce self-assembled monolayers (SAMs) on Au electrodes and the amine terminus was employed for immobilization of biomolecules In an enzyme-amplified sandwich type immunosensor, the polyaniline (PANI) produced enzymatically is attracted by the electrostatic force of the matrix polymer The precipitated PANT was characterized by electrochemical methods