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.

Detection of DNA hybridization by ABEI electrochemiluminescence in DNA-chip compatible assembly.

The electrochemiluminescence (ECL) of a luminol derivate (ABEI) generated both by a carbon electrode and a polypyrrole-coated carbon electrode was examined. It was found that the polypyrrole film (ppy) did not inhibit the ECL. After that, ABEI anchored on a single stranded DNA target (ODNt) has been used for the ECL detection of the hybridization between a complementary single stranded DNA probe (ODNp) covalently linked to a polypyrrole support and the ODNt.