School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China.
Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield S3 7HQ, United Kingdom.
J Agric Food Chem. 2021 Sep 29;69(38):11494-11501. doi: 10.1021/acs.jafc.1c03469. Epub 2021 Sep 16.
A novel multiplex mycotoxin surface-enhanced Raman spectroscopy (SERS) immunoassay was established for the first time on different artificial antigen-modified silica photonic crystal microspheres (SPCMs), which can be integrated into a biochip array to achieve multiplex detection using corresponding antibody-functionalized gold nanoparticles (AuNPs) as the SERS nanotag. The unique optical structure of SPCMs is helpful to find the detection spots easily, accommodate a large amount of probe molecules, and enhance the Raman signal intensity. Such enhancement was confirmed by the simulation result, showing the electric field enhancing effect in SPCMs with AuNPs being 7 times. A competitive SERS immunoassay was established using antigen-modified SPCMs and mycotoxins to compete for binding antibody-functionalized SERS nanotags, displaying broad linear detection ranges of 0.001-0.1 ng/mL for aflatoxin B (AFB), 0.01-10 ng/mL for ochratoxin A (OTA), and 0.001-0.1 ng/mL for zearalenone (ZEN) and low detection limits of 0.82 pg/mL for AFB, 1.43 pg/mL for OTA, and 1.00 pg/mL for ZEN. In the spiked cereal samples, recovery rates of the method were measured in the range of 70.35-118.04% for the three mycotoxins, which was in agreement with that of the traditional enzyme-linked immunosorbent assay method. The SERS immunoassay for mycotoxin detection also showed high specificity and good repeatability and reproducibility. The new microsphere-based SERS immunoassay biochip only requires a one-step reaction and overcomes the disadvantages of fluorescence and chemiluminescence background signals. The work paves the way for further developing SERS-based microsphere suspension arrays for new targets.
建立了一种新型的多重真菌毒素表面增强拉曼光谱（SERS）免疫分析方法，首次在不同人工抗原修饰的硅质光子晶体微球（SPCMs）上进行，该方法可集成到生物芯片阵列中，使用相应的抗体功能化金纳米粒子（AuNPs）作为 SERS 纳米标签进行多重检测。SPCMs 的独特光学结构有助于轻松找到检测点，容纳大量探针分子，并增强拉曼信号强度。通过模拟结果证实了这种增强作用，显示 AuNPs 在 SPCMs 中的电场增强效果为 7 倍。使用抗原修饰的 SPCMs 和真菌毒素建立了竞争性 SERS 免疫分析方法，使真菌毒素竞争结合抗体功能化的 SERS 纳米标签，显示出针对黄曲霉毒素 B（AFB）的 0.001-0.1ng/mL 的宽线性检测范围、针对赭曲霉毒素 A（OTA）的 0.01-10ng/mL 以及针对玉米赤霉烯酮（ZEN）的 0.001-0.1ng/mL，检测限低至 0.82pg/mL 对 AFB、1.43pg/mL 对 OTA 和 1.00pg/mL 对 ZEN。在经过真菌毒素污染的谷物样品中，该方法的回收率在三种真菌毒素的范围内为 70.35%-118.04%，与传统的酶联免疫吸附测定方法一致。用于真菌毒素检测的 SERS 免疫分析还表现出高特异性、良好的重复性和再现性。基于新微球的 SERS 免疫分析生物芯片仅需要一步反应，克服了荧光和化学发光背景信号的缺点。这项工作为进一步开发基于 SERS 的微球悬浮阵列用于新目标铺平了道路。
