Comparison by QCM and photometric enzymatic test of the biotin-avidin recognition on a biotinylated polypyrrole.

By gravimetric measurements using a quartz cristal microbalance (QCM), we have studied the immobilization of biotinylated glucose oxidase enzymes (B-GOx) bound through on an intermediate avidin layer to a biotinylated polypyrrole film. The aim is to assess the amount of B-GOx specifically anchored on the biotinylated polypyrrole/avidin assembly thank to the biotin/avidin interaction between avidin and B-GOx. Indeed the estimated amount from the QCM measurement corresponds to the specific recognition of avidin/B-GOx added to a non-specific recognition (adsorption) of B-GOx.

Study of DNA hybridization on polypyrrole grafted with oligonucleotides by photocurrent spectroscopy.

Recognition of DNA sequences by biochemical sensor is generally performed by analysis after completion of hybridization. Using a technique able to directly translate the biological event into an electrical signal allows the in situ monitoring of the hybridization kinetics. In this aim, the photoelectrochemical behavior of one electroactive polymeric sensor based on a copolymer of polypyrrole and polypyrrole-oligonucleotide has been investigated in aqueous solution.