Synthesis and Characterization of Heparin-Doped Polypyrrole Coatings Using an Electrochemical Quartz Crystal Microbalance (EQCM)

Abstract

Polypyrrole (PPy) films were electrochemically synthesized on an Au/TiO2 coated quartzcrystal electrode in solutions with different heparin (Hep) concentrations. The PPy filmsmorphology was determined by tapping a mode atomic force microscopy (AFM). Theinfluence of the dopant concentration on the coating surface roughness was studied.Electrochemical quartz crystal microbalance (EQCM) results suggest that Hep retained inthe PPy films was bound to thrombin. The adsorbed thrombin amount increased with ahigher coating surface roughness. PPy films doped with Hep are electroactive and showcation exchange properties under oxidation or reduction conditions in a Ringer solution.The pre-oxidized PPy film adsorbed a greater thrombin amount than the freshly one andeven more than the pre-reduced film.