The non-structural protein 1 (NS1) of dengue virus is abundantly circulating in the blood during the acute phase of the dengue infection being correlated with viremia levels and hence can be used to early diagnostic of the dengue hemorrhagic fever. An electrochemical immunosensor based on gold film electrode obtained from a recordable compact disk (CD-trode) was developed for NS1 protein. Anti-NS1 monoclonal antibodies were immobilized on the CD-trode via protein A. The stepwise immobilization of the anti-NS1 was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The analytical response to the NS1 interaction with anti-NS1 immobilized on CD-trode was detected by applying the differential pulse voltammetry technique. The immunosensor showed a linear response from 1 to 100. ng/mL of NS1 and a detection limit of 0.33. ng/mL. This label-free immunosensor exhibited a good reliability for NS1 detection in serum samples presuming an early diagnostic of the dengue virus. © 2012 Elsevier B.V.