In this work,a one-step,simple route towards synthesizing cuprous oxide( Cu2 O) nanoparticles with uniform particle size was explored using chemical reduction method. Then nanomaterial of Cu2 O was characterized by scanning electron microscopy ( SEM). In pH 7. 0 phosphate buffer solution,Cu2 O and Nafion complex modified electrode exhibited a strong electrocatalytic effect to dopamine( DA) compare with the bare glassy carbon electrode. Under the optimized experimental conditions,an electroanalytical system of trace dopamine was established based on chronoamperometry of electrocatalytic properties of Cu2 O modified electrode. The detection limit is 0. 17 μmol·L-1 with the sensitivity of 20. 44 μA mM-1 and the reaction time of less than 3 s in a concentration range of 0. 5~270 μmol·L-1 . The concentration of dopamine was able to be accurately measured at 20 times the AA coexistence due to increase Nafion film. The results of voltammetric determinations show a good reproducibility and stability,and the relative standard deviation ( RSD ) was 3. 3% for the slope of the calibration curve based on the 11 measurements of 50 μM dopamine. Moreover,the developed sensor could be successfully applied to determine dopamine in simulation preparations.%本文采用简单的一步化学还原方法合成了粒径均一的纳米Cu2 O材料并采用扫描电子显微镜对其形貌进行了表征。研究发现,在pH 7．0的磷酸盐缓冲溶液中,采用纳米Cu2 O和Nafion(全氟磺酸离子交换树脂)膜制备的复合修饰电极对多巴胺( DA)呈现出较强的电化学催化作用。优化实验条件后,建立了计时电流法直接测定多巴胺的痕量分析体系。在0．5~270μmol·L-1浓度范围内,多巴胺的阳极峰电流与浓度呈良好的线性关系(r=0．9980),检测限为0．17μmol·L-1,灵敏度为20．44μA mM-1且响应时间不超过3 s。该电极可有效屏蔽抗坏血酸( AA)的干扰,在20倍AA共存下仍能准确地测定DA。对含50μmol·L-1 DA的溶液平行测定11次,相对标准偏差为3．3%,表明修饰电极的重现性和稳定性好。将该修饰电极用于模拟样品中DA的测定,结果令人满意。
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