Development of a sensor based on tetracyanoethylenide (LiTCNE)/poly-L-lysine (PLL) for dopamine determination

The catalytic oxidation of dopamine (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 dopamine (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 μmol l-1 by differential pulse voltammetry (DPV) with a detection limit of 0.5 nmol l-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 dopamine in pharmaceutical formulations and the average recovery for these samples was 101.9 (±0.1)%