Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (10): 1916-1922.doi: 10.3866/PKU.WHXB201407211

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

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.

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

MSC2000: 

  • O641