Surface-enhanced Raman Scattering of Aflatoxin B1 on Silver by DFT Method
- Received Date: 2013-01-23
- Aflatoxin B1, Surface-enhanced Raman scattering spectrum, Pre-resonance Raman spectra, Density functional theory
Abstract: The structure, electrostatic properties, and Raman spectra of aflatoxin B1 (AFB1) and AFB1-Ag complex are studied by density functional theory with B3LYP/6-311G(d,p)/Lanl2dz basis set. The results show that the surface-enhanced Raman scattering (SERS) and pre-resonance Raman spectra of AFB1-Ag complex strongly depend on the adsorption site and the excitation wavelength of the incident light. The SERS factors are found to enhance 102-103 order compared to normal Raman spectrum of AFB1 molecule due to the larger static polarizabilities of the AFB1-Ag complex, which directly results in the stronger chemical enhancement in SERS spectra. The pre-resonance Raman spectra of AFB1-Ag complex are explored at 266, 482, 785, and 1064 nm incident light wavelength, in which the enhancement factors are about 102-104, mainly caused by the charge-transfer ex-citation resonance. The vibrational modes are analyzed to explain the relationship between the vibrational direction and the enhanced Raman intensities.
|Citation:||Si-min Gao, Hong-yan Wang, Yue-xia Lin. Surface-enhanced Raman Scattering of Aflatoxin B1 on Silver by DFT Method[J]. Chinese Journal of Chemical Physics , 2014, 27(2): 131-136. doi: 10.1063/1674-0068/27/02/131-136|