Surface-enhanced Raman scattering (SERS) is a rapid and sensitive analytical technique for detecting fingerprint structures of analyte at low concentrations. However, the lack of uniform and stable substrate limits its wide applications. Here, we demonstrate a novel 1T-MoS₂/AgNCs nanocomposite SERS substrate fabricated on a flexible filter paper for sensitive analysis of pesticide residues in apple fruit. The 1T-MoS₂ nanosheets were synthesized by hydrothermal method and subsequently decorated with AgNCs. Importantly, the MoS₂ nanosheets form a scaffold that physically holds the AgNCs, resulting in the 1T-MoS₂/AgNCs for the adsorption of more target analytes. More importantly, the fibrous structure of the filter paper endows excellent sample collection efficiency. Interestingly, the substrate has remarkable SERS activity attributed to the synergistic effects of (i) the high electromagnetic enhancement generated from the plasmonic AgNCs, and (ii) charge transfer between the MoS₂ nanosheets and the target molecules. The results showed that 1T-MoS₂/AgNCs nanocomposite substrate achieved a record enhancement factor (AEF = 1.78 × 10⁷), a low detection limit (LOD) of 10⁻¹² M, and good reproducibility (RSD = 9.46%) for R6G compared to the other substrates. Also, the SERS substrate is capable of label-free detection of thiram (TRM) and thiabendazole (TBZ) pesticides in real apple juice and peel. The LOD of thiram and thiabendazole were down to 0.15 ppb and 10 ppb, respectively. As a proof-of-concept application, multi-component detection of a mixture of TRM and TBZ was successfully analyzed. Thus, 1T-MoS₂/AgNCs nanocomposite SERS substrate is promising for the ultrasensitive and label-free analysis of diverse pesticide biomarkers in real samples.

表面增强拉曼散射（SERS）是一种用于检测低浓度分析物指纹结构的快速灵敏的分析技术。然而，缺乏均匀和稳定的基底限制了其广泛的应用。在这里，我们展示了一种新颖的1T-MoS ₂ / AgNCs纳米复合材料SERS基质，该基质在柔性滤纸上制造，用于敏感分析苹果果实中的农药残留。1T-MoS ₂纳米片通过水热法合成，然后用AgNCs装饰。重要的是，MoS ₂纳米片形成了物理上可容纳AgNC的支架，从而形成了1T-MoS ₂/ AgNC用于吸附更多目标分析物。更重要的是，滤纸的纤维结构具有出色的样品收集效率。有趣的是，底物具有显着的SERS活性，这归因于（i）等离子体AgNC产生的高电磁增强作用，以及（ii）MoS ₂纳米片与目标分子之间的电荷转移。结果表明，1T-MoS ₂ / AgNCs纳米复合衬底达到了创纪录的增强因子（AEF = 1.78×10 ⁷），低检测限（LOD）为10 ^-12M，与其他底物相比，R6G具有良好的重现性（RSD = 9.46％）。同样，SERS底物能够无标记地检测出真实苹果汁和果皮中的噻兰（TRM）和噻菌灵（TBZ）农药。噻菌灵和噻菌灵的检出限分别降至0.15 ppb和10 ppb。作为概念验证的应用，已成功分析了TRM和TBZ混合物的多组分检测。因此，1T-MoS ₂ / AgNCs纳米复合材料SERS底物有望用于实际样品中多种农药生物标记物的超灵敏和无标记分析。