纳米免疫传感器法快速测定粮油食品中的黄曲霉毒素B_1

A Nano Immunosensor for Rapid Determination of Aflatoxin B_1 in Grain and Oil Food

以改性壳聚糖为固定化材料,包埋固定纳米金胶微粒及黄曲霉毒素B_1抗体制备信号放大型纳米免疫传感器,建立了免疫传感器测定黄曲霉毒素B_1的方法;优化了纳米免疫传感器的制备条件及检测参数;基于AFB_1抗体与抗原之间的特异性免疫反应,以K_3[Fe(CN)_6]为探针,利用循环伏安法和差分脉冲伏安法研究了其免疫反应对传感器响应电流的影响,结果表明免疫响应电流与底液中AFB_1的浓度在0.1~1.1 ng/g范围内成线性关系,其校正曲线方程为I_P=-4.927 4x+15.108(R^2=0.991 2),其最低检测限为0.05 ng/g(S/N=3);该免疫传感器的稳定性和重现性较好。利用该法对花生油、玉米油等实际样品中的AFB_1进行了检测,其回收率为在87.8~98.2%,检测精确度优于ELISA试剂盒法,用于粮油食品中黄曲霉毒素的快速检测是可行的。

Using modified chitosan as immobilizing materials, gold nano particles and aflatoxin B1 antibody were embedded and immobilized to prepare signal - enlarging Nano immunosensor to establish the method of immunosensor to determine aflatoxin Bt in grain and oil food. Preparation conditions and determination parameters of Nano immu- nosensors were optimized; Based on the Specific immune reaction between antibody and antigen of AFB1, the effects of immune response on the immunosensor response current were investigated by cyclic vohammetry and differential pulse voltammetry using K3 [ Fe（CN） 6 ] as the probe. The results showed that the immune response currents formed a linearl relationship with the concentration of aflatoxin B1 in the range of 0.1 ~1.1 ng/g, its calibration curve equa-tion was y = -4.927 4x ＋ 15. 108, R2 = 0. 991 2 with the lowest detection limit of 0.05 ng/g （S/N = 3 ） ;Excellent stability and reproducibility of the immunosensor were observed in the selected condition. The developed method was applied to the determination of aflatoxin B1 in peanut oil, maize and maize oil samples, and the recovery rate was 87.8 ~ 98.2%. Being more precise and accurate than ELISA method, it was practicable for rapid determination of af- latoxin B~ in grain and oil food with simple pretreatment.