Investigation by QCM of the specific and nonspecific avidin interaction onto a biotinylated polypyrrole film

We have studied by gravimetric measurements using a quartz crystal microbalance (QCM), the adsorption of avidin onto a potypyrrole film. From QCM results, it appears that both the thickness and the redox state of polypyrrole strongly influence the avidin adsorption. This nonspecific interaction is larger for a thick film than for a thin one and, also for when the polymer is in its reduced state. We have also investigated by QCM the specific and nonspecific interaction of avidin onto biotinylated polypyrrole films having either a hydrophilic or hydrophobic character. It is shown that the amount of avidin immobilized by specific recognition is almost the same whatever the nature of the Polymer matrix.