Modified electrodes with o-phenylenediamine and p-benzoquinone copolymer were prepared optimizing the conditions to obtain a polymeric film with an adequate intake of copper. Various electrode materials were assayed, and the copolymer deposit was potentiodynamically prepared on a platinum electrode. The film thickness was varied with the number of potentiodynamic cycles. The wide potential window shown by this modified electrode allowed attempting the insertion of copper in the polymeric matrix using several strategies. The response of the electrode was checked in the presence of g-aminobutyric acid (GABA). This way it was possible to obtain an electrode with an adequate and reproducible response for the detection of GABA in the concentration range between 10-4-10-5 mole·L-1 being the reading stable after several measurements