Electrochemical Impedance Spectroscopy Using Interdigitated Gold–Polypyrrole Electrode Combination

physica status solidi (a), vol. 217

Abstract

A novel electrochemical impedance spectroscopy (EIS) sensor design, based on a standard interdigitated electrode arrangement in which the working electrode consists of gold and the combined counter and reference electrodes of polypyrrole doped with polystyrene sulfonate (PPy:PSS), is evaluated for biosensing applications. The performance is successfully proved by immobilization of a thiolated biotin as a self‐assembled monolayer (SAM), followed by streptavidin and a biotinylated horseradish peroxidase. It is shown that specific binding of biomolecules takes place only at the gold electrode. The binding activities are not influenced by the addition of small amounts of the nonionic surfactant Pluronic F‐68. The immobilization process is monitored online with EIS showing an excellent repeatability of the EIS signals in comparison with Au–Au electrode configuration even after electrode regeneration.

Authors 6

1. Tom Kremers Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1 RWTH Aachen University Sommerfeldstraße 24 D-52074 Aachen Germany

2. Nora Menzel Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1 RWTH Aachen University Sommerfeldstraße 24 D-52074 Aachen Germany

   Laboratory for Biomaterials Institute for Biotechnology and Helmholtz-Institute for Biomedical Engineering RWTH Aachen University Pauwelsstraße 20 D-52074 Aachen Germany

3. Dominic Laaf Aachen

   RWTH Aachen University

   Affiliation as printed

   Laboratory for Biomaterials Institute for Biotechnology and Helmholtz-Institute for Biomedical Engineering RWTH Aachen University Pauwelsstraße 20 D-52074 Aachen Germany

4. Viktoria Heine Aachen

   RWTH Aachen University

   Affiliation as printed

   Laboratory for Biomaterials Institute for Biotechnology and Helmholtz-Institute for Biomedical Engineering RWTH Aachen University Pauwelsstraße 20 D-52074 Aachen Germany

5. Lothar Elling Aachen

   RWTH Aachen University

   Affiliation as printed

   Laboratory for Biomaterials Institute for Biotechnology and Helmholtz-Institute for Biomedical Engineering RWTH Aachen University Pauwelsstraße 20 D-52074 Aachen Germany

6. Uwe Schnakenberg corresponding Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1 RWTH Aachen University Sommerfeldstraße 24 D-52074 Aachen Germany