Alsammarraie Fouad K, Lin Mengshi
Food Science Program, Division of Food System & Bioengineering, University of Missouri , Columbia, Missouri 65211-5160, United States.
J Agric Food Chem. 2017 Jan 25;65(3):666-674. doi: 10.1021/acs.jafc.6b04774. Epub 2017 Jan 12.
In recent years, there have been increasing concerns about pesticide residues in various foods. On the other hand, there is growing attention in utilizing novel nanomaterials as highly sensitive, low-cost, and reproducible substrates for surface-enhanced Raman spectroscopy (SERS) applications. The objective of this study was to develop a SERS method for the rapid detection of pesticides that were extracted from different types of food samples (fruit juice and milk). A new SERS substrate was prepared by assembling gold nanorods into standing arrays on a gold-coated silicon slide. The standing nanorod arrays were neatly arranged and were able to generate a strong electromagnetic field in SERS measurement. The as-prepared SERS substrate was utilized to detect carbaryl in acetonitrile/water solution, fruit juices (orange and grapefruit), and milk. The results show that the concentrations of carbaryl spiked in fruit juice and milk were linearly correlated with the concentrations predicted by the partial least-squares (PLS) models with r values of 0.91, 0.88, and 0.95 for orange juice, grapefruit juice, and milk, respectively. The SERS method was able to detect carbaryl that was extracted from fruit juice and milk samples at a 50 ppb level. The detection limits of carbaryl were 509, 617, and 391 ppb in orange juice, grapefruit juice, and milk, respectively. All detection limits are below the maximum residue limits that were set by the U.S. EPA. Moreover, satisfactory recoveries (82-97.5%) were accomplished for food samples using this method. These results demonstrate that SERS coupled with the standing gold nanorod array substrates is a rapid, reliable, sensitive, and reproducible method for the detection of pesticide residues in foods.
近年来，人们对各类食品中的农药残留愈发关注。另一方面，利用新型纳米材料作为表面增强拉曼光谱（SERS）应用中高灵敏度、低成本且可重现的基底受到越来越多的关注。本研究的目的是开发一种SERS方法，用于快速检测从不同类型食品样品（果汁和牛奶）中提取的农药。通过将金纳米棒组装成直立阵列制备了一种新的SERS基底，该直立纳米棒阵列排列整齐，在SERS测量中能够产生强电磁场。所制备的SERS基底用于检测乙腈/水溶液、果汁（橙汁和葡萄柚汁）以及牛奶中的西维因。结果表明，添加到果汁和牛奶中的西维因浓度与偏最小二乘法（PLS）模型预测的浓度呈线性相关，橙汁、葡萄柚汁和牛奶的r值分别为0.91、0.88和0.95。SERS方法能够检测出从果汁和牛奶样品中提取的50 ppb水平的西维因。西维因在橙汁、葡萄柚汁和牛奶中的检测限分别为509、617和391 ppb。所有检测限均低于美国环境保护局设定的最大残留限量。此外，使用该方法对食品样品实现了令人满意的回收率（82 - 97.5%）。这些结果表明，SERS结合直立金纳米棒阵列基底是一种快速、可靠、灵敏且可重现的食品中农药残留检测方法。
