The catalytic oxidation of doparnine (DA) at a LiTCNE (lithium tetracyanoethylenide) film modified electrode is studied by electrochemical approaches. The immobilization of LiTCNE was performed by a polymer (Poly-L-lysine) to prepare this modified electrode and its application for dopamine (DA) determination is described in detail. The modified electrode showed a high activity for the electrooxidation of doparnine (DA) at E-p = 0.20 V versus SCE. The modified electrode presented a wide linear response range for DA from 0.01 up to 10 mu mol 1(-1) by differential pulse voltammetry (DPV) with a detection limit of 0.5 nmol 1(-1). The repeatability of the proposed sensor evaluated in term of relative standard deviation was 3.2% for n = 10. The sensor was applied for the determination of doparnine in pharmaceutical formulations and the average recovery for these samples was 101.9 (+/-0.1)%. (c) 2004 Elsevier Ltd. All rights reserved.