The overall objective of this work is the evaluation of different competitive aptamer assays based on inductively coupled plasma mass spectrometry (ICP-MS) detection for the determination of β-conglutin (food protein allergen from lupin) in flour samples. To this end, two competitive aptamer assay schemes were developed using either thiolated aptamers chemisorbed onto gold nanoparticles (AuNPs) or biotinylated aptamers linked to streptavidin-AuNPs. The influence of ICP-MS detection mode (i.e., conventional vs single particle) on assay performance was explored. In the case of the thiolated aptamer, the limit of detection (LoD) obtained using the single particle mode was improved 2-fold as compared to the LoD provided by the conventional mode. With regards to the biotinylated aptamer, the use of the conventional mode provided a 5-fold improvement of LoD as compared to that obtained for the single particle one. Using the optimized conditions, the best LoD of 2 pM was obtained with the biotinylated aptamer operating with conventional ICP-MS detection. When compared to previous reports using the same aptamer in a competitive assay, the developed method significantly improved the LoD by at least an order of magnitude. Different flour samples containing lupin were successfully analyzed according to European Conformity guidelines for the analysis of food contaminants.

这项工作的总体目标是评估基于电感耦合等离子体质谱 (ICP-MS) 检测的不同竞争性适配体测定法，用于测定面粉样品中的 β-凝集素（来自羽扇豆的食物蛋白过敏原）。为此，使用化学吸附到金纳米粒子 (AuNP) 上的硫醇化适体或与链霉亲和素-AuNP 连接的生物素化适体开发了两种竞争性适体测定方案。探讨了 ICP-MS 检测模式（即常规与单颗粒）对测定性能的影响。在硫醇化适体的情况下，与传统模式提供的 LoD 相比，使用单粒子模式获得的检测限 (LoD) 提高了 2 倍。关于生物素化适体，与单粒子模式相比，使用传统模式可将 LoD 提高 5 倍。使用优化条件，使用常规 ICP-MS 检测操作的生物素化适体获得了 2 pM 的最佳 LoD。与之前在竞争性检测中使用相同适体的报告相比，所开发的方法将 LoD 显着提高了至少一个数量级。根据欧洲食品污染物分析合规指南，成功分析了含有羽扇豆的不同面粉样品。与之前在竞争性检测中使用相同适体的报告相比，所开发的方法将 LoD 显着提高了至少一个数量级。根据欧洲食品污染物分析合规指南，成功分析了含有羽扇豆的不同面粉样品。与之前在竞争性检测中使用相同适体的报告相比，所开发的方法将 LoD 显着提高了至少一个数量级。根据欧洲食品污染物分析合规指南，成功分析了含有羽扇豆的不同面粉样品。