Description:
<jats:title>Abstract</jats:title><jats:p>A DNA biosensor for the detection of specific oligonucleotide sequences of Avian Influenza Virus type H5N1 has been proposed. The NH<jats:sub>2</jats:sub>‐ssDNA probe was deposited onto a gold electrode surface to form an amide bond between the carboxyl group of thioacid and the amino group from ssDNA probe. The signals generated as a result of hybridization were registered in square wave voltammetry and electrochemical impedance spectroscopy in the presence of [Fe(CN)<jats:sub>6</jats:sub>]<jats:sup>3−/4−</jats:sup> as a redox marker. The genosensor is capable to determine 20‐mer and 180‐bp (PCR products) oligonucleotides complementary sequences with detection limit in the fM range. The genosensor displays good selectivity and sensitivity. The 20‐mer as well as 180‐bp oligonucleotides without a complementary sequence generate very low signal.</jats:p>