The reaction of Cu(CH3COO)(2)H2O and Cu(ClO4)(2)center dot 6H(2)O with bis(3,5-dimethylpyrazol-1-yl)methane ligand (L) yielded complexes [cu(cH(3)COO)(2)(L)) (1) and [Cu(L)(2)(H2O)] (CIO4)(2) (2), which were isolated as air -stable solids. The complexes were characterized by electrical conductivity; thermogravimetric analysis; cyclic voltammetry; and Raman, infrared and ultraviolet/visible spectroscopy. The structure of 2 was determined by single -crystal Xray diffraction analysis. Graphite electrodes modified with each of the complexes were used to detect dopamine using differential pulse voltammetry. In the presence of ascorbic acid and uric acid, the highest sensitivity (2.01 mu A mu M-1 cm(-2)) and the lowest detection limit (0.5 mu M) were obtained with the electrode modified with 1. The linearity of the signal, the sensitivity and the detection limit were significantly improved when the solution contained polystyrenesulfonate (PSS-), demonstrating the synergistic effect between the complexes modifying the electrode surface and the PSS- in solution.