基于核酸适配体的侧流层析技术同步检测赭曲霉毒素A和黄曲霉毒素B1

由于简单、低成本和快速的特点，侧流层析分析技术被广泛应用于食品、饲料和农产品中真菌毒素的检测。本实验基于适配体与靶标物特异性结合的原理，建立了基于适配体互补链同时检测赭曲霉毒素A（Ochratoxin A, OTA）和黄曲霉毒素B1（Aflatoxin B1, AFB1）两种真菌毒素的荧光多残留试纸条，通过优化两种适配体的浓度以及缓冲体系的PH值，提高了共同检测OTA和AFB1的灵敏度和准确性。OTA和AFB1的T线（TO和TA）和C线荧光强度比值与对应真菌毒素的浓度对数具有良好的线性关系，线性范围为0.5~50 ng/mL，相关系数r2分别为0.9887和0.9910，检出限低至0.51和0.38 ng/mL。通过对花生和葡萄干进行加标回收和实际样品检测，使用多残留试纸条检测的OTA和AFB1的回收率分别为82.06%~109.69%和83.34%~110.06%，相对标准偏差（Relative Standard Deviation, RSD）为1.89%~8.17%，检测结果与高效液相色谱-串联质谱法（HPLC-MS/MS）一致。该生物传感器可以在20 min内同时检测OTA和AFB1，并且具有成本低、检测速度快和易于操作等优点，可以满足花生和葡萄干等实际样品中OTA和AFB1残留量的现场快速检测的要求，为真菌毒素多残留检测提供理论依据和技术支撑。

Synchronous detection of ochratoxin A and aflatoxin B1 by lateral flow chromatography based on nucleic acid aptamers

Lateral flow chromatography is widely used for the detection of mycotoxins in food, feed and agricultural products because of its simplicity, low cost and fast speed. Based on the principle of specific binding of Cy5 fluorescently labeled aptamer and target, a multi-residue test strip based on the complementary strand of aptamer was established to detect Ochratoxin A(OTA) and Aflatoxin B1(AFB1). The concentration of the two aptamers and pH value of the buffer was optimized to improve the sensitivity and accuracy of detecting OTA and AFB1, making it more suitable for practical applications. The ratio of the fluorescence intensity of the two T-lines (TO and TA) and C-lines has a good linear relationship with the logarithm of the concentrations of OTA and AFB1. The test strip showed an excellent linear relationship in the range from 0.5 to 50 ng/mL with the correlation coefficients (r2) of 0.9887 and 0.9910.The limits of detection of OTA and AFB1 were 0.51 and 0.38 ng/mL, respectively. This aptamer-based multi-residue test strip was successfully applied to the determination of OTA and AFB1in spiked and commercial peanutsand raisins, and the recoveries of the spiked samples were 82.06%-109.69% and 83.34%-110.06%, respectively.The relative standard deviation (RSD) was from 1.89% to 8.17%.The results were consistent with HPLC-MS/MS. The biosensor can simultaneously detect OTA and AFB1 in 20 minutes, and has the advantages of low cost, fast detection speed and easy operation.It can meet the requirements of rapid on-site detection of OTA and AFB1 residues in actual samples such as peanuts and raisins. It provided theoretical basis and technical support for mycotoxin multi residue detection.