电化学免疫传感器法快速测定粮油食品中的苯并(a)芘

采用2.0 G聚酰胺-胺(PAMAM)、石墨烯(GS)和1-丁基-3-甲基咪唑基四氟硼酸盐复合膜修饰玻碳电极(PAMAM /GS/IL/GCE)，包埋固定多环芳烃抗体，构建了一种纳米免疫传感器，用于快速测定粮油食品中的苯并(a)芘(BaP)。在pH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，基于多环芳烃抗体与抗原之间的特异性免疫反应，以K3[Fe(CN)6]为探针，利用循环伏安法和差分脉冲伏安法研究其免疫反应对传感器响应电流的影响。在优化实验条件下，免疫传感器的峰电流随溶液中BaP浓度的增大而减小，且峰电流与BaP浓度在0.1~100 ng/mL范围内呈线性关系，其检测限为0.03 ng/mL（S/N=3）。该免疫传感器的稳定性和重现性较好，利用该法对玉米油和菜籽油等样品中的苯并(a)芘进行检测，回收率在94.46%~103.36%，检测结果与HPLC法基本一致，用于粮油食品中苯并(a)芘的快速检测是可行的。
A nanoimmunosensor for rapid quantification of benzo(a)pyrene (BaP) in food was constructed by modifying the glassy carbon electrode (GCE) with 2.0 G polyamidoamine (PAMAM), graphene (GS), and a 1-butyl-3-methylimidazolium tetrafluoroborate composite film and by immobilizing the antibody against polycyclic aromatic hydrocarbons (PAHs) on the surface of the GCE. On the basis of the specific immune reaction between the anti-PAH antibody and antigen, the effects of the immune response on the immunosensor response current were studied by cyclic voltammetry and differential pulse voltammetry using K3[Fe(CN)6] as the probe in phosphate buffer (pH=7.0) containing 1 mmol/L K3[Fe(CN)6] and 0.1 mmol/L KCl. At optimized experimental parameters, the peak response current of the immunosensor decreased with the increasing BaP concentration, and the response current showed a linear relation with the concentration of BaP in the range 0.1–100 ng/mL, with a detection limit of 0.03 ng/mL (S/N=3). The prepared anti-PAH/PAMAM/GS/IL/GCE immunosensor showed excellent stability and reproducibility. The newly developed method was applied to analysis of BaP content in peanut and rapeseed oil samples, and the recovery rate was in the range of 94.46~103.36%. The results were generally consistent with those obtained by high-performance liquid chromatography (HPLC) method; therefore, the proposed method is feasible for rapid quantification of BaP in grain- and oil-related foods.