A robust flexible paper-plasmonic hybrid SERS substrate is reported by exploiting the intrinsic properties of filter paper and anisotropic Ag@SiO₂ nanocubes. The fibrous structure of paper promotes the assemblage of sharp-edged nanostructures which significantly improved the SERS activity. An inexpensive sensing platform with reasonable distribution and interparticle spacing of nanocubes was obtained by filtering Ag@SiO₂ through a miniaturized filter paper. The thin silica shell improved the stability and interparticle spacing of silver nanocubes in the sensing platform, rendering enhanced SERS activity through the plasmon-coupling effect as compared to a conventional rigid substrate. Assessment of the analytical performance of the substrate for melamine quantification showed a good linearity (R² = 0.9948) up to 1 mg L⁻¹ with a limit of detection of 0.06 mg L⁻¹. The detection limit in liquid milk was down to 0.17 mg L⁻¹, which is below the permissible residue limit signifying adequate sensitivity for real sample analysis with less sample treatment.

中文翻译：

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负载 Ag @ SiO ₂纳米立方体的微型滤纸作为混合柔性等离子SERS底物，用于痕量三聚氰胺检测†

通过利用滤纸和各向异性的Ag @ SiO ₂纳米立方体的内在特性，报道了一种坚固的柔性纸-等离子体混合SERS基底。纸的纤维结构促进了锋利的纳米结构的组装，从而显着提高了SERS活性。通过过滤Ag @ SiO ₂获得了具有合理分布和纳米粒子间距的廉价传感平台。通过小型滤纸。二氧化硅薄壳改善了感测平台中银纳米立方体的稳定性和颗粒间的间距，与传统的刚性基板相比，通过等离振子耦合效应增强了SERS活性。对底物的三聚氰胺定量分析性能的评估显示，线性良好（R ² = 0.9948），最高至1 mg L ^-1，检出限为0.06 mg L ^-1。液态奶中的检出限降至0.17 mg L ^-1，这低于允许的残留限度，表明对于较少样品处理的真实样品分析具有足够的灵敏度。