Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (09): 2044-2050.doi: 10.3866/PKU.WHXB201205311

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Surface-Enhanced Raman Spectra of Aflatoxin B1 Adsorbed on Silver Clusters

GAO Si-Min, WANG Hong-Yan, LIN Yue-Xia, LI Ru-Hu   

  1. School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, P. R. China
  • Received:2012-04-09 Revised:2012-05-30 Published:2012-08-02
  • 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 (10974161, 11174237), Fundamental Research Funds for the Central Universities, China (SWJTU09CX079, SWJTU12CX084, 2010ZT06), and Outstanding Student-Funded Project of Southwest Jiaotong University, China (2010XS43).

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Abstract:

The structures, surface-enhanced Raman scattering (SERS), and pre-resonance Raman spectra (SERRS) of Aflatoxin B1 (AFB1)-Agn (n=2, 4, 6) complexes were calculated using density functional theory (DFT) with the B3LYP/6-311G(d, p) (C, H, O)/LanL2DZ (Ag) basis set. The results show that the SERS enhancement factors were about 102-103 for the AFB1-Agn (n=2, 4, 6) complexes, respectively. This is due to the C＝O stretch of the pyran ring and the larger static polarizability of the three complexes. The SERS spectra were consistent with the experimental results. The SERRS spectra of the three complexes were obtained by excitation at 407.5, 446.2, and 411.2 nm, which were close to the electronic excitation energy of absorption spectra as determined by time-dependent density functional theory (TDDFT). The SERRS enhancement factors caused by the charge-transfer excitation resonance were about 104, which corresponds to the Ag―O stretching.

Key words: Density functional theory, Aflatoxin B1, Complexes AFB1-Agn (n＝2, 4, 6), Surface-enhanced Raman scattering, Surface-enhanced resonance Raman spectrum