In situ synthesis and copolymerization of oligonucleotides on conducting polymers

Two strategies of DNA biochip construction on conducting polymers are inves tigated. The first involves a direct electro-copolymerization of pyrroleoli gonucleotides (oligonucleotides tethered to a pyrrole group) with the pyrro le leading to a polypyrrole film bearing the oligonucleotides. Successive c opolymerizations allow the transformation of a microelectrode array into a DNA array. The second methodology involves a direct in situ synthesis of ol igonucleotides on a conducting polymer used as an organic electrode. In thi s way a 5' electrolabile protecting group, p-nitrobenzoyl, was used. In ord er to construct short oligonucleotide sequences, the other protecting group s of the bases have also to be modified, preliminary results based on this technology are shown.