纳米Fe3O4-还原氧化石墨烯复合修饰玻碳电极的制备及电化学检测多巴胺

通过电化学还原法制备纳米Fe₃O₄-还原氧化石墨烯复合修饰玻碳（Fe₃O₄-rGO/GCE）电极，用于多巴胺（DA）的检测。采用SEM、TEM和循环伏安对纳米Fe₃O₄-rGO复合材料进行表征。在pH为7.0的磷酸盐缓冲液（PBS）中，采用循环伏安法研究了DA在纳米Fe₃O₄-rGO/GC上的电化学行为。实验结果表明，较裸GC电极和rGO修饰（rGO/GC）电极，由于纳米Fe₃O₄与rGO的协同作用，纳米Fe₃O₄-rGO/GC显著增大了Fe₃O₄-rGO/GC复合材料电极电化学活性面积和氧化峰电流强度i_pa。DA的浓度在6.0×10^-8~2.0×10^-6 mol/L和2.0×10^-6~8.0×10^-5 mol/L范围内，与氧化峰电流强度i_pa呈良好的线性关系，检出限达4.0×10^-9 mol/L（信噪比S/N=3）。抗坏血酸和尿酸共存物几乎不干扰DA的测定，选择性高。Fe₃O₄-rGO/GC修饰电极用于盐酸DA注射液中的DA含量测定，获得结果较好，回收率为97.1%~103.9%。

Fabrication of nano Fe3O4-reduced graphene oxide composite modified glassy carbon electrode and its application for the determination of dopamine

The nano Fe₃O₄-reduced graphene oxide composite modified glassy carbon (Fe₃O₄-rGO/GC) electrode was fabricated by electrochemical reduction method, and used for the determination of dopamine (DA).The nano Fe₃O₄-rGO composites were characterized by SEM, TEM and cyclic voltammetry. The electrochemical behavior of DA was investigated in pH=7.0 phosphate buffer saline (PBS) by cyclic voltammetry. Compared with bare GC electrode and rGO-modified (rGO/GC) electrode, the electrochemical active area and the oxide peak current i_pa of Fe₃O₄-rGO/GC electrode increase significantly, owing to the synergistic action between nano Fe₃O₄ and rGO. The oxide peak current i_pa shows good linear relationship with the concentration of DA in the range of 6×10^-8-2×10^-6 mol/L and 2×10^-6-8×10^-5 mol/L. The detection limit is 4.0×10^-9 mol/L (signal-noise ratio S/N=3).The determination of DA hardly interfere with the coexistence of ascorbic acid and uric acid. The proposed method is further applied to the determination of DA in DA injections with satisfied results, and the recovery of DA is 97.1%-103.9%.