Zamora-Peredo Luis, García-Ramirez Josué Ismael, García-Velasco Amado Carlos, Hernández-Torres Julián, García-González Leandro, Bizarro Monserrat, Báez-Rodríguez Adriana
Centro de Investigación en Micro y Nanotecnología, Universidad Veracruzana, Adolfo Ruiz Cortines 455, Boca del Río 94294, Mexico.
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico.
Nanomaterials (Basel). 2021 Dec 16;11(12):3414. doi: 10.3390/nano11123414.
Surface enhanced Raman spectroscopy (SERS) is considered a versatile and multifunctional technique with the ability to detect molecules of different species at very low molar concentration. In this work, hierarchical ZnO microspheres (ZnO MSs) and Ag/ZnO MSs were fabricated and decorated by hydrothermal and photodeposition methods, respectively. For Ag deposition, precursor molar concentration (1.9 and 9.8 mM) and UV irradiation time (5, 15, and 30 min) were evaluated by SEM, TEM, X-ray diffraction and Raman spectroscopy. X-ray diffraction showed a peak at 37.9° corresponding to the (111) plane of Ag, whose intensity increases as precursor concentration and UV irradiation time increases. SEM images confirmed the formation of ZnO MSs (from 2.5 to 4.5 µm) building by radially aligned two-dimensional ZnO nanosheets with thicknesses below 30 nm. The Raman spectra of Ag/ZnO MSs exhibited a vibration mode at 486 cm which can be directly associated to Ag deposition on ZnO MSs surface. The performance of SERS substrate was evaluated using rhodamine 6G. The SERS substrate grown at 9.8 mM during 30 min showed the best SERS activity and the ability to detect methylene blue at 10 M.
表面增强拉曼光谱（SERS）被认为是一种多功能技术，能够在极低摩尔浓度下检测不同种类的分子。在这项工作中，分别通过水热法和光沉积法制备并修饰了分级结构的ZnO微球（ZnO MSs）和Ag/ZnO MSs。对于Ag沉积，通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射和拉曼光谱对前驱体摩尔浓度（1.9和9.8 mM）和紫外线照射时间（5、15和30分钟）进行了评估。X射线衍射显示在37.9°处有一个对应于Ag（111）面的峰，其强度随着前驱体浓度和紫外线照射时间的增加而增强。扫描电子显微镜图像证实了由厚度小于30 nm的径向排列的二维ZnO纳米片构建的ZnO MSs（直径为2.5至4.5 µm）的形成。Ag/ZnO MSs的拉曼光谱在486 cm处表现出一种振动模式，这可以直接与Ag沉积在ZnO MSs表面相关联。使用罗丹明6G对SERS基底的性能进行了评估。在9.8 mM下生长30分钟的SERS基底表现出最佳的SERS活性，并能够检测到10 M的亚甲基蓝。
