A new method for the immobilisation of antibodies in conducting polymers

In this work, we report on the antigen–antibody conducting polymer-based sensors that transduce antigen–antibody interactions into measurable changes in electrochemical properties. These polymers are derived from polypyrroles and polybithiophenes functionalized by an activated ester. Two new thiophene and pyrrole derivatives containing activated ester groups covalently linked to a conjugated backbone via a linear arm spacer have been synthesized. These monomers undergo a facile electropolymerisation at the electrode surface and can be easily functionalized by an antigen group. The electrochemical results show that the cyclic voltammograms of antigen-polymer are modified when the antibody–antigen interaction occurs. Furthermore, the electrochemical response of polymer/antigen and polymer/antigen–antibody systems depends on the hydrophobic character of the polymers.