AbstractThe article describes an aptamer affinity column for selective solid-phase extraction of aflatoxin B2 (AFB2). Amino-modified aptamer against AFB2 was immobilized on CNBr-activated Sepharose through a covalent bond. The effects of oligosorbents based on 3′- or 5′-amino-modified sequences with a C6 or a C7 spacer arm were evaluated by UV spectroscopy at 260 nm. The extraction recovery was evaluated by HPLC with fluorometric detection. The extraction of AFB2 was optimized. Under the optimum conditions, the aptamer affinity column has a linear response to AFB2 in the range of 0.5–80 ng, with a capacity of 84.6 ng. Control supports without immobilized aptamers and a nonspecific oligosorbent immobilized with a negative control oligonucleotide were studied in order to demonstrate selectivity. The method was tested with spiked peanut sample (0.5–50 μg·kg−1 AFB2) and gave average recoveries of 80.9% and a mean relative standard deviation of 1.9%. The limit of detection is 25 pg·mL−1. This is much lower than the maximum residue limits suggested by the European Union. The columns can be re-used up to five times without any loss of performance. The oligosorbent was also applied to clean-up of AFB2 from peanut sample extracts before HPLC analysis. Results were further confirmed by ultra-fast liquid chromatography with tandem mass spectrometry. Conceivably, the method may also be applied to other samples, such as food, agricultural products, and traditional Chinese medicines. Graphical abstractSchematic illustration of the fabrication procedures of aptamer affinity column, AAC (a), its principle of aptamer bound to aflatoxin B2 (b) and the obtained AAC (c).

中文翻译：

---

一种基于寡吸附剂的适体亲和柱，用于在 HPLC 荧光检测前选择性提取黄曲霉毒素 B2

摘要本文介绍了一种用于选择性固相萃取黄曲霉毒素 B2 (AFB2) 的适体亲和柱。针对 AFB2 的氨基修饰适体通过共价键固定在 CNBr 活化的 Sepharose 上。通过紫外光谱在 260 nm 处评估基于具有 C6 或 C7 间隔臂的 3'- 或 5'-氨基修饰序列的低聚吸附剂的影响。萃取回收率通过 HPLC 与荧光检测进行评估。优化了AFB2的提取。在最佳条件下，适配体亲和柱对 AFB2 的线性响应范围为 0.5-80 ng，容量为 84.6 ng。为了证明选择性，研究了没有固定适体的对照支持物和固定有阴性对照寡核苷酸的非特异性寡吸附剂。该方法使用加标花生样品 (0. 5–50 μg·kg-1 AFB2)，平均回收率为 80.9%，平均相对标准偏差为 1.9%。检测限为 25 pg·mL-1。这远低于欧盟建议的最大残留限量。色谱柱最多可重复使用五次而不会降低性能。在进行 HPLC 分析之前，低聚吸附剂还用于净化花生样品提取物中的 AFB2。结果通过超快速液相色谱和串联质谱进一步证实。可以想象，该方法也可以应用于其他样品，如食品、农产品和中药。图形摘要 适配体亲和柱的制备过程示意图，AAC（a），其适配体与黄曲霉毒素 B2 结合的原理（b）和获得的 AAC（c）。