Wang Shiyao, Hao Qingxiang, Zhao Yanan, Chen Yisheng
College of Food Science and Engineering, Shanxi Agricultural University, Taigu 030801, Shanxi, China.
Institute of Food Nutrition and Safety, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China.
J Agric Food Chem. 2023 Mar 29;71(12):4982-4989. doi: 10.1021/acs.jafc.3c00134. Epub 2023 Mar 15.
In recent years, growing food safety and quality concerns have emerged and created an urgent need for the development of rapid and reliable food control technologies. This study proposes a novel surface-enhanced Raman spectroscopy (SERS) substrate printing technology that utilizes commercial filter paper functionalized by silver nanoparticles. We modified the Automatic TLC Sampler using a two-dimensional (2D) printer. The modification allows for various sampling modes which can be applied to 2D printing. The shape and size of nano silver on the substrate were determined, and the substrate sensitivity, uniformity, and stability were evaluated. As demonstrated by the experimental outcomes, the proposed technology is highly sensitive and reproducible, that is, the limit of quantitation was 10 mg/kg, and the spot-to-spot and block-to-block Raman intensity variations were below 4.2%. We also successfully applied the technology to pears and apples for thiram recognition, yielding outstanding detectability down to 2.5 × 10 and 3.9 × 10 mg/mL (equal to 2.5 × 10 and 3.9 × 10 mg/kg), respectively. These were well below the maximum residue limit (7 mg/kg). More importantly, the linear relationships between thiram levels and the SERS intensity allow for sensitive monitoring of minute variations in agricultural insecticide residues. This proposed detection method can realize in situ detection with a strong signal fingerprint.
近年来，食品安全和质量问题日益受到关注，迫切需要开发快速可靠的食品检测技术。本研究提出了一种新型的表面增强拉曼光谱（SERS）底物打印技术，该技术利用经银纳米颗粒功能化的商用滤纸。我们使用二维（2D）打印机对自动薄层色谱进样器进行了改装。这种改装允许各种可应用于二维打印的采样模式。确定了底物上纳米银的形状和尺寸，并评估了底物的灵敏度、均匀性和稳定性。实验结果表明，所提出的技术具有高度的灵敏度和可重复性，即定量限为10 mg/kg，斑点间和块间拉曼强度变化低于4.2%。我们还成功地将该技术应用于梨和苹果中的福美双识别，检测限分别低至2.5×10和3.9×10 mg/mL（相当于2.5×10和3.9×10 mg/kg）。这些均远低于最大残留限量（7 mg/kg）。更重要的是，福美双水平与SERS强度之间的线性关系允许对农业杀虫剂残留的微小变化进行灵敏监测。这种提出的检测方法可以实现具有强信号指纹的原位检测。
