Abstract

A sandwich plasmonic coupled surface enhanced Raman spectroscopy (SERS) tape is proposed prepared by peeling the chemical printed silver nanocorals (AgNCs) from Cu sheet with adhesive tape, which can sample targets from food surface and sandwich them between substrates and Cu sheet for SERS detection. The solid-to-solid transformation method for fabricating SERS tapes can effectively avoid the weakening of tape stickiness during the preparation process. The sandwich plasmonic coupled structure of AgNC substrate, targets, and Cu sheet display excellent SERS activity (EF = 1.62 × 10⁷) for sensitive determination of analytes. In addition, due to the high heat conductivity of Cu sheet, the thermal effect of laser irradiation during SERS detection cannot damage the AgNC tapes, which ensures the reproducibility of subsequent quantification. The sandwich plasmonic coupled SERS tape is demonstrated to quantify malachite green (MG) and methyl parathion (MP) with good linear coefficients (> 0.98) by two typical calibration plots under different concentration ranges. The limit of detection (LOD) of the method is 0.17 ng/cm² and 0.48 μg/cm² (S/N = 3) for MG and MP. This method can realize the quantitative determination of MP and MG on the surface of fruits and fish scale with recoveries of 93–113%. The satisfactory detection results demonstrate the proposed sandwich plasmonic coupled AgNC tape can be successfully applied to SERS-based point-of-care testing (POCT) for pesticide residue determination, which will provide a new path for designing and constructing SERS tapes.

Graphical Abstract

摘要

提出一种三明治等离子体耦合表面增强拉曼光谱（SERS）胶带，通过用胶带将化学印刷的银纳米珊瑚（AgNCs）从铜片上剥离来制备，该胶带可以从食品表面采样目标并将其夹在基材和铜片之间进行SERS检测。采用固-固转化方法制备SERS胶带，可以有效避免制备过程中胶带粘性减弱的情况。 AgNC 基板、靶材和铜片的夹层等离子体耦合结构表现出优异的 SERS 活性 (EF = 1.62 × 10 ⁷ )，可用于灵敏测定分析物。此外，由于Cu片的高导热性，SERS检测时激光照射的热效应不会损坏AgNC带，保证了后续定量的重现性。通过不同浓度范围下的两个典型校准图，证明夹心等离子体耦合 SERS 胶带能够以良好的线性系数 (> 0.98) 定量孔雀石绿 (MG) 和甲基对硫磷 (MP)。对于 MG 和 MP ，该方法的检测限 (LOD) 分别为 0.17 ng/cm ²和 0.48 μg/cm ² (S/N = 3)。该方法可实现水果和鱼鳞表面MP和MG的定量测定，回收率为93%~113%。令人满意的检测结果表明，所提出的夹心等离子体耦合AgNC胶带可以成功应用于基于SERS的现场护理测试（POCT）农药残留测定，这将为设计和构建SERS胶带提供新途径。