Due to its wide application, procymidone has become one of the pesticides with high detection rates in supervision and sampling. Therefore, it is necessary to establish a rapid and efficient method for the detection of procymidone. However, an important bottleneck restricting the development of rapid detection methods of procymidone is that its specific recognition elements are rarely reported. In this work, Capture-SELEX and post-SELEX were used in aptamer screening, and the obtained aptamers were used to construct an aptamer-based lateral flow assay (LFA). Firstly, a specific aptamer Seq15 was obtained for procymidone by Capture-SELEX, and its dissociation constant (Kd) was 24.22 nM. Secondly, post-SELEX was used to analyze and modify Seq15 to improve its performance, and the Kd of the truncated sequence Seq15-2 was 21.28 nM. In addition to this, the broad-specificity aptamer Seq17-1 was obtained via post-SELEX. Seq17-1 could broadly recognize dicarboximide fungicides (procymidone, iprodione, chlozolinate, dimethachlon and vinclozolin) and their metabolic derivative (3,5-dichloroaniline). Finally, the specific aptamer-based LFA of procymidone was constructed, and the limit of detection (LOD) was 0.79 ng/mL. Meanwhile, the LODs of dicarboximide fungicides and their metabolic derivative were 0.62, 0.64, 0.71, 0.69, 0.64 and 0.66 ng/mL, respectively. The above LFAs were highly specific and stable, and had been successfully used for the detection of vegetable samples. Under the combination of Capture-SELEX and Post-SELEX, this study not only provides specific recognition elements for rapid detection of procymidone, but also provides new ideas for the discovery of broad-specificity aptamers. Combining broad-specificity primary detection and single-specificity quantification, a composite aptamer-based LFA detection platform has been developed, which significantly improves detection efficiency.

中文翻译：

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Capture-SELEX 和 Post-SELEX 的组合用于速克利特异性适体选择和广泛特异性适体发现，以及基于适体的侧流检测的开发


由于应用广泛，腐霉利已成为监督抽检检出率较高的农药之一。因此，有必要建立一种快速、高效的腐霉利检测方法。然而，制约腐霉利快速检测方法发展的一个重要瓶颈是其特异性识别元件鲜有报道。本工作采用Capture-SELEX和post-SELEX进行适体筛选，并利用获得的适体构建基于适体的侧流分析（LFA）。首先，通过Capture-SELEX获得腐霉利的特异性适配体Seq15，其解离常数（Kd）为24.22 nM。其次，使用post-SELEX对Seq15进行分析和修改以提高其性能，截短序列Seq15-2的Kd为21.28 nM。除此之外，还通过 post-SELEX 获得了广泛特异性的适体 Seq17-1。 Seq17-1 可以广泛识别二甲酰亚胺类杀菌剂（速克灵、异菌脲、氯唑啉、敌草酮和乙烯菌核利）及其代谢衍生物（3,5-二氯苯胺）。最后，构建了腐霉利基于核酸适配体的 LFA，检测限 (LOD) 为 0.79 ng/mL。同时，二甲酰亚胺杀菌剂及其代谢衍生物的 LOD 分别为 0.62、0.64、0.71、0.69、0.64 和 0.66 ng/mL。上述LFA具有高度特异性和稳定性，已成功用于蔬菜样品的检测。在Capture-SELEX和Post-SELEX的结合下，该研究不仅为快速检测腐霉利提供了特异性识别元件，也为发现广泛特异性适配体提供了新思路。 结合广泛特异性初级检测和单特异性定量，开发了基于复合适配体的LFA检测平台，显着提高了检测效率。