Potentiometric monitoring DNA hybridization with polyaniline/Nylon-6 working electrode

Electrically conducting polymers are useful in various applications such as transistors and sensors. A potentiometric pH meter has been developed using polyaniline based working electrode and with improved selectivity using ionophores, the polyaniline based potentiometer has been applied to monitor various ions mainly in environmental applications. The polyaniline working electrode can be used to monitor not only the binding of a biological ionic macromolecules on polyaniline surface but also the binding of the adsorbed macromolecule with another macromolecule. We present first how the working electrode was prepared by polymerization of aniline in Nylon-6 matrix to provide the mechanical strength and then how single strand oligonucleotide probe binds with polyaniline surface. We then present how an electrode modification with mercaptoethanol results in a surface protected against non-specific binding and then finally we present the results of monitoring the complimentary strand binding leading to the formation of the double strand DNA.