喷墨打印纸质SERS基底应用于水果中福美双的检测

采用喷墨打印技术在疏水性相片纸表面沉积银纳米薄膜，制备了一种高效的纸质表面增强拉曼散射（SERS）基底（银纳米薄膜/相片纸），并利用接触角测量仪与扫描电子显微镜（SEM）表征相片纸书写前后的浸润性和表面形貌.通过模拟福美双在果皮表面及果汁中的残留状态，对银纳米薄膜/相片纸基底的应用潜力进行评价.研究发现，该基底可以直接识别出果汁溶液或果皮表面掺杂的福美双分子，不需作任何预处理.对掺杂福美双的果汁最低检测的质量浓度低至0.024 mg∙L^-1，且特征峰强度与浓度间具有较好的线性关系；对果皮表面残留福美双分子的检测限为0.25 ng∙cm^-2.此外，在吸附福美双/果汁的基底表面随机选取10个点，研究银纳米薄膜/相片纸的均匀性，经计算1 142和1 377 cm^-1处的特征峰的相对标准偏差分别为7.8%和5.7%.结果表明：银纳米薄膜/相片纸在农药残留检测方面具有潜在的应用前景.

Application of inkjet printed paper-based SERS substrate in thiram detection in fruits

The efficient AgNPs/photographic surface enhanced Raman scattering(SERS) paper substrate was prepared by inkjet printing silver ink on photographic paper, for which the wettability and surface morphology were represented by contact angle meter and scanning electron microscope(SEM). The application of AgNPs/photographic paper for detecting pesticide residues was studied by simulating the residual states of thiram on peels and in juice. It was found that thiram molecules mixed in juice or on peels could be directly recognized by the substrate without any treatment. The minimum detection concentration of thiram in juice was 0.024 mg∙L^-1, in which a good linear relationship between characteristic peak intensity and concentration was obtained The detection limit of thiram on the two peels was both 0.25 ng∙cm^-2. In addition, ten spots were selected from the same substrate to study the uniformity randomly. The relative standard deviations of the characteristic peak intensities at 1 142 and 1377 cm^-1 of thiram were 7.8% and 5.7%, respectively. The results showed that AgNPs/photographic paper substrate had great potential in the detection of pesticide residues.