High sensitive voltammetric sensor based on Pt/CNTs nanocomposite modified ionic liquid carbon paste electrode for determination of Sudan I in food samples

In this work, a simple and high sensitivity electrochemical sensor was developed to determine Sudan I based on Pt/CNTs nanocomposite ionic liquid modified carbon paste electrode (Pt/CNTs/ILCPE) using cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) methods. The novel sensor exhibited an obviously catalytic activity towards the oxidation of Sudan I, which can be confirmed by the increased oxidation peak current and the decreased oxidation peak potential when compared with the bare carbon paste electrode (CPE). The electron transfer coefficient (alpha), diffusion coefficient (D), and charge transfer resistance (R-ct) of Sudan I at the modified electrode were calculated. The linear response range and detection limit were found to be 0.008-600 mu mol L-1 and 0.003 mu mol L-1, respectively. Other species did not interfere with the determination of Sudan I at a surface of propose sensor in the optimum condition. The proposed sensor was successfully applied for the determination of Sudan I in food samples with satisfactory results. (C) 2013 Elsevier Ltd. All rights reserved.