Herein, we reported a simple, flexible and sensitive surface-enhanced Raman scattering (SERS) substrate to detect methyl parathion residues in real life. The substrate was fabricated by filter paper and gold nanoparticles (Au NPs) with excellent reproducibility and stability. First, Au NPs were synthesized by the seed mediated growth method and assembled to the filter paper through immersion. The Raman probe molecule 4-MBA was used to evaluate performance of the substrate for an optimized signal using a portable Raman spectrometer coupled with 785 nm laser. Then, the paper-based substrate was applied to detect methyl parathion standard solution whose detection limit was down to 0.011 μg/cm2, and the linear range was between 0.018 μg/cm2 and 0.354 μg/cm2. Afterwards, actual sample (apple) spiked with methyl parathion was taken to verify the practicality of the substrate by a simple way of "press-peel off". The recovery rate was ranged from 94.09% to 98.72%, indicating that this method is reliable in actual sample detection without complicated pretreatment steps. This work demonstrates that the flexible paper-based substrate combined with portable Raman instruments can be potentially applied to on-site detection of hazardous substances in the field of food safety.

中文翻译：

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基于纸质SERS的灵活底物策略，可快速检测水果表面上的甲基对硫磷。

在本文中，我们报道了一种简单，灵活且灵敏的表面增强拉曼散射（SERS）底物，用于检测现实生活中的甲基对硫磷残留。用滤纸和金纳米颗粒（Au NPs）制成的基材具有出色的重现性和稳定性。首先，通过种子介导的生长方法合成金纳米颗粒，并通过浸渍将其组装到滤纸上。使用便携式拉曼光谱仪结合785 nm激光，拉曼探针分子4-MBA用于评估优化信号的底物性能。然后，将纸基基材应用于检测极限值降至0.011μg/ cm2的甲基对硫磷标准溶液，线性范围为0.018μg/ cm2至0.354μg/ cm2。之后，实际样品（苹果）中掺有甲基对硫磷，可通过“剥离”的简单方法来验证基材的实用性。回收率范围为94.09％至98.72％，表明该方法在实际样品检测中可靠，无需复杂的预处理步骤。这项工作表明，与便携式拉曼仪器结合的基于纸质的柔性基底可潜在地应用于食品安全领域中的有害物质现场检测。