基于疏水滤纸的金纳米花SERS基底高灵敏检测牛奶中的三聚氰胺

Hydrophobic Filter Paper-Based Gold Nanoflowers SERS Substrate for Highly Sensitive Detection of Melamine in Milk

将海胆状金纳米花(GNFs)疏水滤纸基底和表面增强拉曼散射(SERS)技术相结合,实现了牛奶中三聚氰胺的高灵敏检测。由左旋多巴还原制备的GNFs拥有许多尖锐突起和尖端可激发强局部电磁场增强(EM),产生大量的“热点”,提高SERS检测的灵敏度。采用疏水滤纸作为衬底,改进了纸基衬底上纳米材料分布不均匀的缺点。进而评估了SERS基底的灵敏度、稳定性和重现性。通过对加标牛奶中三聚氰胺的定量检测,在1×10^(-3)~1×10^(-9) mol/L范围内,牛奶中三聚氰胺的浓度对数与SERS强度呈良好的线性关系,检测限低至43pmol/L,远低于同类检测方法。本方法检测实际样品结果与液相色谱法检测结果对比无显著性差异(p>0.05)。GNFs疏水滤纸SERS基底具有高灵敏度、稳定性、重现性和实用性的优点,为牛奶等其他食品中三聚氰胺的定量检测提供了参考。

Highly sensitive detection of melamine in milk was achieved by using sea urchin-like gold nanoflowers(CNFs)of hydrophobic filter paper substrate combined with surface-enhanced Raman scattering(SERS)technology.GNFs prepared by levodopa reduction possess many sharp protrusions and tips that can stimulate strong localized electromagnetic enhancement(EM),creating a large number of"hot spots"and improving the sensitivity of SERS detection.The use of hydrophobic filter paper as the substrate improves the uneven distribution of nanomaterials on the paper-based substrate and the lack of sensitivity.The sensitivity,stability and reproducibility of the SERS substrate were then evaluated.By quantifying melamine in spiked milk,the logarithm of melamine concentration in milk showed a good linear relationship with the SERS intensity in the range of 1×10^(-3)~1×10^(-9)mol/L,and the limit of detection(LOD)was as low as 43 pmol/L,which was much lower than that of the similar detection methods.Moreover,the results of this method for detecting the actual samples were not significantly different from those detected by liquid chromatography(p>O.05).Hydrophobic filter paper-based GNFs SERS substrate offers the advantages of high sensitivity,stability,reproducibility and practicality,providing a reference for the quantitative determination of melamine in other foodstuffs such as milk.