| 摘 要： | Dependence of surface-enhanced Raman scattering (SERS) from Calf thymus DNA on anions is inves- tigated.With the silver colloid,the bands at 732,960 and 1333 cm~(-1) for adenine (A),1466 cm~(-1) for deoxyribose,and 1652 cm~(-1) for the C=O group of thymine (T) are observably enhanced.With the pres- ence of the C1 or SO~-anions,the bands at 732 and 1326/1329 cm-1 for the symmetric stretching and skeletal vibrational modes of adenine (A) are dramatically enhanced,and the enhancement effect with the SO_4~(2-) ion is more than that with the Cl~-ion.The experimental results show that the DNA molecule can be adsorbed on the silver colloid particles through the C_6N and N_7 of adenine (A),the C=O of thymine (T) and deoxyribose.Moreover,the formed hydrogen bonding of the Cl~-or SO_4~(2-) ions to the C_6NH_2 group of adenine (A) can induce larger C_6N electronegativity,which is favor for the C_6N/N_7 cooperative adsorption on the (Ag)_n~ colloid particles.
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