物理化学学报 >> 2014, Vol. 30 >> Issue (10): 1916-1922.doi: 10.3866/PKU.WHXB201407211

催化和表面科学 上一篇    下一篇

黄曲霉素B2分子吸附在银团簇的表面增强拉曼散射机理

高思敏1, 王红艳2, 林月霞1, 吴颖曦2, 胡军1   

  1. 1. 西南交通大学峨眉校区基础课部, 四川峨眉 614202;
    2. 西南交通大学物理科学与技术学院, 成都 610031
  • 收稿日期:2014-05-22 修回日期:2014-07-21 发布日期:2014-09-30
  • 通讯作者: 王红艳 E-mail:hongyanw@home.swjtu.edu.cn
  • 基金资助:

    国家自然科学基金（11174237），国家重点基础研究发展计划（973）（2013CB328904），四川省应用基础项目（2013JY0035）及中央高校基本科研业务费专项资金资助

Surface-Enhanced Raman Scattering Mechanism of Aflatoxin B2 Molecule Adsorbed on Silver Cluster

GAO Si-Min1, WANG Hong-Yan2, LIN Yue-Xia1, WU Ying-Xi2, HU Jun1   

  1. 1. Division of Foundation Courses, E-Mei Campus, Southwest Jiaotong University, E-Mei 614202, Sichuan Province, P. R. China;
    2. School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, P. R. China
  • Received:2014-05-22 Revised:2014-07-21 Published:2014-09-30
  • Contact: WANG Hong-Yan E-mail:hongyanw@home.swjtu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (11174237), National Key Basic Research Program of China (973) (2013CB328904), Application Basic Program of Sichuan Province, China (2013JY0035), and Fundamental Research Funds for the Central Universities, China.

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摘要：

采用密度泛函理论（DFT）B3LYP方法，6-311G（d，p）（C，H，O）/LANL2DZ（Ag）基组，计算了黄曲霉素B2（AFB2）分子吸附在Ag2团簇的表面增强拉曼散射（SERS）光谱和预共振拉曼光谱，并与实验结果比较. 结果显示：AFB2分子在基态Ag2团簇表面吸附时，增强因子最大达到102，对应吡喃（pyrane）环C=O伸缩振动，主要是由AFB2分子周围化学环境改变而引起的基态静极化率改变导致的化学增强. 不同激发波长下的AFB2分子预共振拉曼光谱的增强强度不同：电荷转移态激发波长为1144 和544 nm时拉曼信号增强了102倍，而选择电荷转移预共振波长432和410 nm作为入射光时，其拉曼信号增强了104倍，增强机理为银团簇和黄曲霉素分子之间的电荷转移共振增强. 因此通过改变入射光波长，选择电荷转移共振激发波长，更有利于强致癌物AFB2分子的痕量检测.

关键词: 黄曲霉素B2, 表面增强拉曼散射光谱, 预共振拉曼光谱, 密度泛函理论

Abstract:

The surface-enhanced Raman scattering (SERS) spectrum and pre-resonance Raman spectra of Aflatoxin B2 (AFB2) adsorbed on silver cluster were calculated by density functional theory (DFT) methods with the B3LYP/6-311G (d,p)(C, H, O)/LanL2DZ(Ag) basis set. The results show that the SERS enhancement factors were 102, and this belongs to the C=O stretching vibration of the pyrane ring because of the larger static polarizability of the complex. The pre-resonance Raman spectra of the AFB2-Ag2 complex were explored at 1144 and 544 nm, which corresponds to charge transfer excitation energy, and its enhancement factor was 102. The pre-resonance enhancement factor was 104 when incident light charge transfer pre-resonant wavelengths of 432 and 410 nm were selected. These come from a charge transfer resonance enhancement between the silver cluster and the AFB2 molecule. Therefore, changing the wavelength of the incident light is more conducive to the trace detection of the strong carcinogen AFB2.

Key words: Aflatoxin B2, Surface-enhanced Raman scattering spectrum, Pre-resonant Raman spectrum, Density functional theory