An electrochemical immunosensor for the rapid determination of aflatoxin B1 (AFB1) in foods has been fabricated by employing chitosan, graphene and 1-butyl-3-methyl imidazolium tetrafluoroborate composite film to immobilize AFB1 antibody onto the surface of glassy carbon electrode. Based on the specific immune reaction between AFB1 antibody and antigen, the effects of immune response on the response current of the immunosensor were investigated by cyclic voltammetry and differential pulse voltammetry using K3[Fe(CN)6] as the probe in phosphate buffer solution (pH 7.0) with 1 mmol/L K3[Fe(CN)6] and 0.1 KCl. Under the optimized experimental conditions, the reduction in the peak current of the immunosensor increased with the increase in the logarithm of the concentration of AFB1 in solution, showing a linear relationship in the AFB1 concentration range of 0.1–8.1 ng/mL with limit of detection (LOD) of 0.04 ng/mL (RSN= 3). Excel ent stability and repeatability of the prepared immunosensor were observed under the selected condition. The recovery rate of AFB1 in peanut and corn oil samples was in the range of 94.73%–104.41%. The results from this method wel agreed with those obtained by high performance liquid chromatography method, and so it is practicable for the rapid determination of AFB1 in food.%采用壳聚糖、石墨烯和1-丁基-3-甲基咪唑基四氟硼酸盐复合膜修饰玻碳电极，包埋固定黄曲霉毒素B1（aflatoxin B1，AFB1）抗体，构建了一种免疫传感器，用于快速测定食品中的AFB1。在pH值为7.0含1 mmol/L K3[Fe(CN)6]和0.1 mmol/L KCl的磷酸盐缓冲溶液中，基于AFB1抗体与抗原之间的特异性免疫反应，以K3[Fe(CN)6]为探针，运用循环伏安法和差分脉冲伏安法研究免疫反应对传感器响应电流的影响。在优化实验条件下，免疫传感器峰电流的降低值随溶液中AFB1质量浓度对数的增大而增大，且二者在0.1～8.1 ng/mL范围内呈线性关系，其检出限为0.04 ng/mL（RSN=3）。该免疫传感器的稳定性和重复性较好，利用该法对花生和玉米油样品中AFB1进行检测，回收率为94.73%～104.41%，检测结果与高效液相色谱法基本一致，用于食品中AFB1的快速检测是可行的。
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