Modified electrode with reduced graphene oxide/poly(3-hydroxyphenylacetic acid): a new platform for oligonucleotide hybridization

This paper reports a new platform for oligonucleotide hybridization, prepared by electropolymerization of 3-hydroxyphenylacetic acid onto gold electrode modified with reduced graphene oxide. Electrochemical polymerization indicated that reduced graphene oxide was able to oxidize the monomer in lower potential than the gold electrode. Their structural, morphological, and electrochemical properties were evaluated by Fourier transform infrared spectroscopy, elemental analysis, atomic force microscopy, scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The new platform exhibited high efficiency for immobilization and hybridization detection of oligonucleotides through both direct electrochemical oxidation of guanine residues and indirect oxidation of the electroactive intercalator, ethidium bromide. The genosensor could detect the complementary sequence with a detection limit of 10.4 pmol L −1 . Graphical abstract ᅟ