This work describes the development of electrochemical sensors based on graphite–polyurethane composite (GPU) modified with aluminophosphate zeolite type 5 (AlPO-5) and nickel (II) incorporated aluminophosphate type 5 (NiAlPO-5), in order to evaluate their performance for determination of Cu2+ in ethanol biofuel. These electrodes were initially characterized by cyclic voltammetry. The obtained results revealed that the NiAlPO-5 with Ni/Al ratio 0.5 presented the best response in terms of sensitivity, and peak width at half height of Cu2+ voltamogramm, which indicate that on these conditions the NiAlPO-5 electrode is viable for determination of this ion in biofuel samples by square wave stripping voltammetry. The obtained results revealed that the presence of Ni in the zeolite structure (NiAlPO-5) improves the electrical properties, and increases the peak current for Cu2+ in comparison with the electrode based in AlPO-5. The proposed method presented a linear response for Cu2+ with good results for limit of detection (9.4×10−9 mol L−1), accuracy (recovery of 115 %) and precision (RSD of 5.9 %).

中文翻译：

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基于NiAlPO-5的电化学传感器测定乙醇生物燃料中的Cu2+

这项工作描述了基于石墨-聚氨酯复合材料 (GPU) 的电化学传感器的开发，该复合材料用 5 型铝磷酸盐 (AlPO-5) 和镍 (II) 掺入了 5 型铝磷酸盐 (NiAlPO-5)，以评估它们的性能乙醇生物燃料中Cu2+的测定。这些电极最初通过循环伏安法进行表征。所得结果表明，Ni/Al 比为 0.5 的 NiAlPO-5 在灵敏度和 Cu2+ 伏安图半峰宽方面表现出最佳响应，这表明在这些条件下 NiAlPO-5 电极可用于测定通过方波溶出伏安法测定生物燃料样品中的这种离子。所得结果表明，沸石结构 (NiAlPO-5) 中 Ni 的存在改善了电性能，与基于 AlPO-5 的电极相比，增加了 Cu2+ 的峰值电流。所提出的方法对 Cu2+ 呈现线性响应，在检测限 (9.4×10−9 mol L−1)、准确度（回收率为 115%）和精密度（RSD 为 5.9%）方面具有良好的结果。