In the present paper, the synthesis of cobalt ferrite/reduced graphene oxide (Co₂Fe₂O₄/rGO) composite and its use for the simultaneous determination of uric acid (UA), xanthine (XA), and hypoxanthine (HX) is demonstrated. Cobalt ferrite hollow spheres were synthesized by using the carbonaceous polysaccharide microspheres prepared from a D-glucose solution as templates, followed by calcination. The CoFe₂O₄/rGO composite was prepared with the ultrasound-assisted method. The obtained material was characterized by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, EDX elemental mapping, and nitrogen adsorption/desorption isotherms. The electrochemical behavior of UA, XA, and HX on the CoFe₂O₄/rGO-modified electrode was studied with cyclic voltammetry and differential pulse voltammetry (DPV). The modified electrode exhibits excellent electrocatalytic activity towards the oxidation of the three compounds. The calibration curves for UA, XA, and HX were obtained over the range of 2.0–10.0 μM from DPV. The limits of detection for UA, XA, and HX are 0.767, 0.650, and 0.506 μM, respectively. The modified electrode was applied to the simultaneous detection of UA, XA, and HX in human urine, and the results are consistent with those obtained from the high-performance liquid chromatography technique.

中文翻译：

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CoFe2O4 /还原氧化石墨烯修饰电极同时伏安法测定尿酸，黄嘌呤和次黄嘌呤

本文研究了钴铁氧体/氧化石墨烯（Co ₂ Fe ₂ O ₄ / rGO）复合材料的合成及其在同时测定尿酸（UA），黄嘌呤（XA）和次黄嘌呤（HX）中的应用。演示。通过使用由D-葡萄糖溶液制备的碳质多糖微球作为模板，然后煅烧，合成钴铁氧体空心球。CoFe ₂ O ₄/ rGO复合材料采用超声辅助方法制备。通过使用X射线衍射，扫描电子显微镜，X射线光电子能谱，EDX元素标测和氮吸附/解吸等温线来表征获得的材料。用循环伏安法和差示脉冲伏安法（DPV）研究了UA，XA和HX在CoFe ₂ O ₄ / rGO修饰电极上的电化学行为。修饰的电极对三种化合物的氧化表现出优异的电催化活性。以上的2.0〜10.0的范围内，获得了UA，XA，和HX的校准曲线 μ从DPV微米。检测UA，XA，和HX是0.767，0.650的极限，和0.506  μM分别。将该修饰电极用于人尿中UA，XA和HX的同时检测，结果与高效液相色谱技术相符。