中文摘要：

采用一种温和且简单的原位生长法将铜纳米粒子和石墨烯非共价键合,形成一种对莱克多巴胺催化活性高的复合纳米新材料Cu NPs/PAA/GR。该材料用扫描电镜表征形貌,用阻抗表征修饰电极。不同扫速和p H值条件下,以其修饰玻碳电极构建的电化学体系受吸附控制,莱克多巴胺在该电极表面的反应机理属两电子转移过程。体系中电化学参数为：电子转移数（n）=1.7,修饰电极的有效面积为3.57 cm^2,为裸电极的12.6倍,电极吸附量（Гs）为1.98×10^-12mol/cm^2。采用微分脉冲伏安法进行检测,莱克多巴胺的浓度在1～30μmol/L范围内呈良好线性关系（r^2=0.990 2）,检出限（S/N=3）为18.3 nmol/L。该传感器经济易制备、灵敏性高、稳定性与重现性好。将该传感器用于猪肉中莱克多巴胺的检测,其回收率为97.0%～102.5%,相对标准偏差为2.8%～3.2%。

英文摘要：

A moderate and simple in-situ growth approach was adpoted to bond coppernanoparticles noncovalently to graphene for preparation of Cu NPs/PAA/GR nanocomposites which were used for electrocatalysis of ractopamine（RAC）. The morphology of the material was observed by scanning electron microscopy（SEM）,and the state of the modified glassy carbon electrode was investigated by electrochemical impedance（EIS）. Tests at various scan rates and p H conditions indicated that the modified electrode has an adsorption-controlled electrochemical system. The mechanism for the electrode reaction for ractopamine involves a two-electron transter process accompanied by a deprotonation step. Electrochemical parameters were calculated as follows： the electron transfer number（n） was1. 7,the effective area for the Cu NPs/PAA/GR/GCE electrode was 3. 57 cm^2,12. 6 times as large as bare electrode,and the adsorption capacity（Гs） value was 1. 98 × 10^-12 mol/cm^2. Under the optimal conditions by differential pulse voltammetric measurement,the calibration curve of RAC was linear in the range of 1-30 μmol/L（r^2= 0. 990 2） with a detection limit（S/N = 3） of 18. 3 nmol/L.With advantages of facile fabrication,high sensitivity,good stability and high reproducibility,the sensor was applied in the detection of ractopamine in pork samples with recoveries of 97. 0%-102. 5% and relative standard deviations（RSD） of 2. 8%-3. 2%.