化学学报 ›› 2019, Vol. 77 ›› Issue (10): 1024-1030.DOI: 10.6023/A19050191 上一篇    下一篇

研究论文

g-C3N4/Ag纳米复合材料表面增强拉曼基底对婴幼儿糖果中的罗丹明B的痕量检测

马超, 武佳炜, 朱琳, 韩晓霞, 阮伟东, 宋薇*(), 王旭*(), 赵冰   

  1. 吉林大学理论化学研究所 超分子结构与材料国家重点实验室 长春 130012
  • 投稿日期:2019-05-23 发布日期:2019-07-22
  • 通讯作者: 宋薇,王旭 E-mail:weisong@jlu.edu.cn;wxu@jlu.edu.cn
  • 基金资助:
    项目受国家自然科学基金(21473068);项目受国家自然科学基金(21711540292);项目受国家自然科学基金(21773080);吉林省科技发展计划(20180101295JC)

Trace Detection of Rhodamine B in Infant Candy by g-C3N4/Ag Nanocomposite as Surface-Enhanced Raman Scattering Substrate

Ma, Chao, Wu, Jiawei, Zhu, Lin, Han, Xiaoxia, Ruan, Weidong, Song, Wei*(), Wang, Xu*(), Zhao, Bing   

  1. State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130012, China
  • Received:2019-05-23 Published:2019-07-22
  • Contact: Song, Wei,Wang, Xu E-mail:weisong@jlu.edu.cn;wxu@jlu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China(21473068);Project supported by the National Natural Science Foundation of China(21711540292);Project supported by the National Natural Science Foundation of China(21773080);the Jilin Province Science and Technology Development Plan Project(20180101295JC)

近年来, 由婴幼儿食品中存在非法添加剂所引起的食品安全问题已经受到了广泛的关注. 表面增强拉曼散射(SERS)技术可以对食品中被禁止添加的常用染料分子罗丹明B (RhB)进行快速无损超灵敏的检测. 通过在类石墨相氮化碳(g-C3N4)纳米片上组装Ag纳米粒子的方式构筑了g-C3N4/Ag复合材料, 并采用透射电子显微镜(TEM)、紫外可见近红外分光光度计(UV-Vis)、X射线衍射仪(XRD)、荧光光谱仪和共聚焦显微拉曼光谱仪(Raman)对复合材料的形貌和结构进行了表征. g-C3N4纳米片不仅具有高度的离域π共轭体系和良好的吸附染料分子的性能, 而且可以作为Ag纳米粒子的载体, 使Ag纳米粒子均匀稳定地分散在其表面. 通过控制实验条件, 优化了测试过程中的pH及基底与RhB的结合时间, 详细探究pH对基底表面等离子共振的影响和对探针分子SERS强度的影响. 由于基底与探针分子之间的静电相互作用及π-π相互作用, 基底可以对阳离子染料进行大量地富集, 从而实现对其检测. 在最佳的实验条件下, 在1.0×10 –9~1.0×10 –6 mol/L浓度范围内, SERS强度与RhB浓度之间成线性关系, 最低检测限为0.39 nmol/L. 另外这种基底也可以对婴幼儿食用的棒棒糖中添加的RhB分子实现痕量检测. 总而言之, g-C3N4/Ag纳米复合物是一种均一、稳定、高灵敏的SERS基底, 可以简单快速地实现对罗丹明B的痕量检测.

关键词: 表面增强拉曼光谱, g-C3N4/Ag纳米复合材料, 罗丹明B, 糖果, 痕量检测

In recent years, food safety problems caused by illegal additions in infant foods have received widespread attention. Surface-enhanced Raman scattering (SERS) technique is used to rapidly and non-destructively detect the banned RhB that is usually added in food. In this study, we have prepared g-C3N4/Ag composites via a simple method successfully, their morphology and structure were characterized by transmission electron microscope (TEM), ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), fluorescence spectrophotometer and confocal micro-Raman spectrometer (Raman). The g-C3N4 nanosheet possesses good adsorption performance due to its highly delocalized π-conjugated system, which acts as a carrier for Ag nanoparticles. Therefore, Ag nanoparticles are more uniformly and stably distributed on the surface of g-C3N4 nanosheets to form g-C3N4/Ag nanocomposite, which can be used for rapid adsorption and trace detection of RhB. In the experiment, the pH of the test and the absorbed time between the substrate and RhB were optimized. The influence of pH on the SPR of the substrate and the SERS intensity of the probe molecule were investigated in detail. As g-C3N4/Ag nanocomposite shows a significant higher absorption in the visible region around 500 nm than Ag nanoparticles, g-C3N4/Ag nanocomposite is more favorable for SPR absorption. A wide SPR absorption range is achieved due to the synergy between g-C3N4 and Ag nanoparticles, providing an improved SERS enhancement performance. Under the optimal experimental conditions by using RhB as probe molecule, an enhancement factor of 7.6×10 5 is achieved. Due to the electrostatic interaction and π-π interaction between the substrate and the probe molecules, the substrate can enrich in a large amount of cationic dyes, offering a detection of RhB. The g-C3N4/Ag SERS substrate can be used to detect RhB with a linear relationship from 1.0×10 –9 to 1.0×10 –6 mol/L and a detection limit as low as 0.39 nmol/L. In addition, the g-C3N4/Ag nanocomposite SERS substrate can also detect trace amounts of RhB molecules in the commercially available rainbow lollipops with a high sensitivity, and the recovery were 93.6%~95.04%. In summary, the g-C3N4/Ag nanocomposite is not only a SERS substrate with high sensitivity, uniformity and stability, but also can be used as a rapid trace detection method of Rhodamine B in real food and environment.

Key words: surface enhanced Raman spectroscopy (SERS), g-C3N4/Ag nanocomposites, Rhodamine B, candy, trace detection