In this paper, we report the highly selective and sensitive electrochemical determination of dopamine (DA) based on an iron oxide nanoparticle-(Fe₂O₃ NP) capped graphene sheet (GRS) modified glassy carbon electrode (GCE). The Fe₂O₃ NPs were synthesized by a pyrophoric technique and their nanocomposite with GRS was prepared by a simple sonochemical method. The as-prepared Fe₂O₃ NP/GRS nanocomposite was characterized using scanning electron microscopy, electron dispersive X-ray spectroscopy, Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy. As expected, the proposed sensor exhibits a wide linear range from 0.01 to 195.18, a low detection limit (LOD) of 0.004 μM for the DPV technique and a broad linear range from 0.006 to 635 μM, and a very low detection limit of 0.001 μM for the amperometric technique. Moreover, it shows excellent selectivity of DA even in the presence of a 20-fold higher concentration of potential interferences. The practical applicability of the reported sensor was recorded in human serum and urine samples. Finally, all electrochemical studies confirmed the excellent electrocatalytic activity of the Fe₂O₃ NP/GRS nanocomposite as a DA sensor.

中文翻译：

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氧化铁纳米粒子修饰石墨烯片痕量电化学测定生物样品中神经递质多巴胺

在本文中，我们报道了基于氧化铁纳米粒子-（Fe ₂ O ₃ NP）包覆的石墨烯片（GRS）修饰的玻碳电极（GCE）的多巴胺（DA）的高选择性和灵敏的电化学测定。通过发火技术合成了Fe ₂ O ₃ NP，并通过简单的声化学方法制备了与GRS形成的纳米复合材料。制备的Fe ₂ O ₃NP / GRS纳米复合材料的特征在于使用扫描电子显微镜，电子色散X射线光谱，拉曼光谱，X射线衍射，傅立叶变换红外光谱和电化学阻抗谱。如预期的那样，建议的传感器具有0.01到195.18的宽线性范围，DPV技术的0.004μM的低检测限（LOD）和0.006到635μM的宽线性范围以及0.001μM的很低检测限用于安培技术。而且，即使在潜在干扰浓度高20倍的情况下，它也显示出出色的DA选择性。报告的传感器的实际适用性记录在人的血清和尿液样本中。最后，所有电化学研究均证实了Fe ₂的优异电催化活性O ₃ NP / GRS纳米复合材料用作DA传感器。