School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, United Kingdom.
Anal Chim Acta. 2022 Jul 25;1218:340000. doi: 10.1016/j.aca.2022.340000. Epub 2022 May 27.
Mycotoxin contamination is a serious global issue in food safety. The accurate detection of mycotoxins in complex samples, particularly via a portable detection system that realizes multi-analyte detection, remains a great challenge. Here, a polystyrene (PS)-mediated surface-enhanced Raman scattering (SERS) aptasensor was designed for ultrasensitive and simultaneous detection of multiple mycotoxins in food samples. First, the novel Raman tags were prepared using PS as nanocontainer to encapsulate abundant Raman reporters. The PS nanocontainer with Raman reporters was then functionalized by aptamer as an effective target-recognition platform. Second, the single-strand binding protein modified magnetic nanoparticles (MNPs@SSB) were used as a magnetic capture substrate. When the target mycotoxin was present and recognized by its aptamer, the combination of PS-Apt and mycotoxins can hinder the binding between PS-Apt and MNPs@SSB. Consequently, after the magnetic separation and treatment by THF solution, fewer biological-silent reporter probes were released from PS, causing the reduction of SERS signal as a function of target mycotoxins concentration. Due to the high loading capacity of PS and the excellent signal conversion and amplification of aptamer-assisted SERS assay, the proposed strategy is reliable and ultrasensitive for the determination of multiple mycotoxins. The limit of detection was as low as 0.159 fg L, 2.015 fg L, and 1.561 fg L for ZEN, OTA and AFB, respectively. This strategy not only raises a new idea for designing novel Raman tag, but also broadens the application of SERS for multiple detection of trace target.
真菌毒素污染是食品安全领域的一个严重全球性问题。在复杂样品中准确检测真菌毒素，特别是通过实现多分析物检测的便携式检测系统，仍然是一个巨大的挑战。在这里，设计了一种基于聚苯乙烯（PS）介导的表面增强拉曼散射（SERS）适体传感器，用于食品样品中多种真菌毒素的超灵敏和同时检测。首先，使用 PS 作为纳米容器制备了新型拉曼标签，以封装丰富的拉曼报告分子。然后，通过适体将带有拉曼报告分子的 PS 纳米容器功能化，作为有效的靶标识别平台。其次，将单链结合蛋白修饰的磁性纳米颗粒（MNPs@SSB）用作磁性捕获基底。当存在目标真菌毒素并被其适体识别时，PS-Apt 和真菌毒素的结合可以阻止 PS-Apt 和 MNPs@SSB 之间的结合。因此，在磁分离和 THF 溶液处理后，从 PS 中释放出更少的生物静默报告探针，导致 SERS 信号随目标真菌毒素浓度的减少而减少。由于 PS 的高负载能力和适体辅助 SERS 分析的优异信号转换和放大，该策略可靠且对多种真菌毒素的检测具有超灵敏性。ZEN、OTA 和 AFB 的检测限分别低至 0.159 fg L、2.015 fg L 和 1.561 fg L。该策略不仅为设计新型拉曼标签提出了新的思路，而且拓宽了 SERS 用于痕量目标多检测的应用。
