中文摘要：本研究设计制作了一种均相电化学免疫传感平台用于灵敏地检测食材中的黄曲霉毒素B1(AFB1)。在最佳条件下电化学检测信号随AFB1量的增加而降低，动态检测范围0.01-30ng/mL，检测限4.8pg/mL；此外，该系统的精度和重现性可以接受；最后，进一步评估了用该方法分析自然污染或人工添加AFB1的花生样品，结果与用商业AFB1 ELISA试剂盒的相吻合。
外文摘要：A new homogeneous electrochemical immunosensing platform was designed for sensitive detection of aflatoxin B1 (AFB1) in foodstuff. The system consisted of anti-AFB1 antibody labeled DNA1 (Ab-DNA1), AFB1–bovine serum albumin (BSA)-conjugated DNA2 (AFB1-DNA2), and methylene blue functionalized hairpin DNA. Owing to a specific antigen–antibody reaction between anti-AFB1 and AFB1–BSA, the immunocomplex formed assisted the proximity hybridization of DNA1 with DNA2, thus resulting in the formation of an omega-like DNA junction. Thereafter, the junction opened the hairpin DNA to construct a new double-stranded DNA, which could be readily cleaved by exonuclease III to release the omega-like DNA junction and methylene blue. The dissociated DNA junction could repeatedly hybridize with residual hairpin DNA molecules with exonuclease III-based isothermal cycling amplification, thereby releasing numerous free methylene blue molecules into the detection solution. The as-produced free methylene blue molecules could be captured by a negatively charged indium tin oxide electrode, each of which could produce an electronic signal within the applied potentials. On introduction of target AFB1, the analyte competed with AFB1-DNA2 for the conjugated anti-AFB1 on the Ab-DNA1, subsequently decreasing the amount of omega-like DNA junctions formed, hence causing methylene blue labeled hairpin DNA to move far away from the electrode surface. Under optimal conditions the detectable electrochemical signal decreased with increasing amount of target AFB1 in a dynamic working range of 0.01–30 ng mL-1 with a detection limit of 4.8 pg mL-1. In addition, the precision and reproducibility of this system were acceptable. Finally, the method was further evaluated for analysis of naturally contaminated or AFB1-spiked peanut samples, giving results that matched well with those obtained with a commercial AFB1 ELISA kit.
外文关键词：Electrochemical immunoassay；Aflatoxin B1；Proximity ligation reaction；Omega-likeDNA junction；Isothermal nucleic acid cycling amplification
作者：Tang, J；Huang, YP；Liu, HQ；Zhang, CC；Tang, DP
作者单位：Jiangxi Normal Univ
期刊名称：ANALYTICAL AND BIOANALYTICAL CHEMISTRY
期刊影响因子：3.125
出版年份：2016
出版刊次：30
点击下载：通过邻近杂交诱导形成Ω形DNA结，用核酸外切酶III触发等温循环信号放大对食材中黄曲霉毒素B1进行均相电化学免疫检测