基于多壁碳纳米管免疫传感器法快速测定食品中的莱克多巴胺

以改性壳聚糖包埋固定羧基化多壁碳纳米管和莱克多巴胺抗体，构建免疫传感器用于莱克多巴胺的检测。以K3[Fe(CN)6]为探针，利用循环伏安法表征传感器构建过程和差分脉冲伏安法探究莱克多巴胺抗体/抗原间免疫反应对电流的影响。结果表明，在优化条件下，免疫响应电流与溶液中莱克多巴胺质量浓度的立方根在0.05～4.05 ng/mL范围内呈线性关系，其线性方程为Ip=－4.524 4CRAC1/3＋14.259（R2= 0.990 4 ），最低检测限为0.08 ng/mL（RSN=3）；所构建的免疫传感器的特异性、稳定性和重复性良好。该法对猪肉、羊肉等样品进行检测，其检测结果与国标方法高效液相色谱法一致，检测快捷方便，可用于食品中莱克多巴胺的快速检测。

An Immunosensor for Rapid Determination of Ractopamine in Foods Based on Multi-Walled Carbon Nanotubes

A highly sensitive nanoimmunosensor for the determination of ractopamine (RAC) in food samples was
constructed based on a glass carbon electrode modified with carboxylic multi-walled carbon nanotubes/chitosan (MWNTs-
COOH/CS) composite film. Based on the specific immune reaction between antibody and antigen for RAC, the effect
of immune response on immunosensor response current was investigated by cyclic voltammetry and differential pulse
voltammetry using K3[Fe(CN)6] as the probe. The results showed that immune response currents increased linearly with the
cube root of RAC concentration in the range of 0.05–4.05 ng/mL (Ip = − 4.524 4CRAC 1/3 + 14.259, R2 = 0.990 4) with limit
of detection (LOD) of 0.08 ng/mL (RSN = 3). Excellent specificity, stability and reproducibility of the prepared MWNTs-
COOH/CS/RAC-anti immunosensor were observed under the selected conditions. The developed method was applied to the
determination of RAC in pork, beef, mutton, and chicken samples. The results agreed well with those obtained by HPLC
method. Being faster than HPLC method, this immunosensor is practicable for rapid determination of RAC in food samples.