the invention relates biosensor comprising a conductive or semi - conductive support and an intercalator polymer , wherein the intercalator polymer comprises monomer units of formula wherein p is an electropolymerizable moiety selected among the group consisting in pyrrole , acetylene , phenol , aniline , thiophene , carbazole and azulene ; sp is a spacer , and im is an intercalator . the invention also relates to a method for the detection of a dna sequence with the biosensor , comprising the steps of : hybridizing the dna sequence with a dna probe for forming a dsdna incubating the biosensor with the dsdna for anchoring the dsdna to the intercalator detecting the quantity of dsdna on the biosensor .