多巴胺在氧化锌纳米棒嵌入石墨修饰电极上的电化学行为及测定

Electrochemical Behavior and Determination of Dopamine at ZnO Nanorods Intercalated Graphite Modified Electrode

采用水热法制备了氧化锌纳米棒,用扫描电子显微镜、红外光谱等测试方法对其进行表征,通过嵌入式修饰方法,将制备出的氧化锌纳米棒嵌入到石墨电极中制成修饰电极。用循环伏安法和差分脉冲伏安法研究了多巴胺在修饰电极上的伏安行为和反应机理。结果表明,该修饰电极对多巴胺显示出良好的响应,不仅使峰电流增加,并使多巴胺的氧化峰电位负移68 mV。该电极过程的动力学参数:电子转移数n=2,电子转移系数α=0.48。多巴胺的脉冲峰电流与其浓度在5.0×10-7～1.0×10-4 mol/L内呈良好的线性关系,检出限为1.0×10-7 mol/L(S/N=3)。对1.0×10-5 mol/L的多巴胺平行测定8次的相对标准偏差(RSD)为3.42%。用本法测定了盐酸多巴胺注射液中多巴胺的含量,加标回收率为94.83%～104.5%。

Hydrothermally prepared zinc oxide nanorods were characterized by scanning electron microscopy and infrared spectroscopy. The zinc oxide nanorod modified graphite electrode was prepared by intercalation for dopamine determination. Voltammetric behavior and reaction mechanism of dopamine at the modified graphite electrode were investigated with cyclic voltammetry and differential pulse vohammetry. The results showed that there were good vohammetric responses for dopamine at the modified electrode under optimal conditions, with peak currents greatly enhanced and an negative shift of anodic peak potential by 68 inV. Kinetic properties of the electrochemical process were also obtained ： the number of transfer electrons （n） is 2 and the electron transfer coefficient （a） is 0. 48. The peak currents of differential pulse voltammetry of dopamine are linear in the ranges of 5.0 × 10 -7 - 1.0 × 10 - 4 moL/L with a detection limit of 1.0 ×10 -7 mol/L at the signal-to-noise of 3. Relative standard deviation（RSD） is 3.42% for eight parallel detections of 1.0 × 10-5 mol/L dopamine. The recoveries of this proposed method for determination of dopamine hydrochloride injection solutions are in the range of 94, 83% - 104. 5%.