同时检测玉米中黄曲霉毒素B1和赭曲霉毒素A的时间分辨荧光免疫层析试纸条的研制

研究制备了一种可同时快速定量检测黄曲霉毒素B1 (aflatoxin B1,AFB1)和赭曲霉毒素A(ochratoxin A,OTA)的二联时间分辨荧光免疫层析试纸条.采用铕系时间分辨荧光微球分别标记AFB1和OTA单克隆抗体,优化荧光微球活化pH值、标记的抗体浓度、荧光探针使用量、检测线包被原浓度、质控线羊抗鼠Ig...

Development of a Time-resolved Fluorescence Immunochromatographic Strip for the Simultaneous Detection of Aflatoxin B1 and Ochratoxin A in Corn Samples

In this study, a time-resolved fluorescence immunochromatographic assay (TRFICA) for detecting aflatoxin B1 (AFB1) and ochratoxin A (OTA) simultaneously was developed. Europium-based time-resolved fluorescent microspheres were used to label anti-AFB1 monoclonal antibody and anti-OTA monoclonal antibody. Various factors such as pH for the activation of fluorescent microspheres, concentration of labeled antibodies, dosage of fluorescent probes, concentration of coating antigens for test line, concentration of goat anti-mouse IgG for quality control line, and sample pretreatment conditions were optimized. Under the optimal conditions, the assay showed half inhibition concentration (IC50) values of 1.58 and 3.91 μg/kg , linear ranges of 0.26–9.73 and 1.14–13.29 μg/kg, and visible limits of detection (vLOD) of 3.70 and 5.55 μg/kg for AFB1 and OTA, respectively. The cross-reactivity rates of this method with aflatoxin analogues and ochratoxin B were 12%–62% and 58%, respectively, without cross-reactivity with other mycotoxins. The recoveries of the two toxins spiked in corn samples were 92%–103%, with coefficients of variation (CV) less than 15%. The results of this method for real samples coincided with those of high performance liquid chromatography (HPLC) and commercial colloidal gold strip. The TRFICA strip was stored at 4 ℃ for more than 5 months with good stability. To sum up, this immunochromatographic strip is sensitive, accurate, rapid and easy to operate, and is very suitable for rapid screening of AFB1 and OTA in food and agricultural products.