一种新型肽核酸单体的FTIR,FT-Raman光谱及SERS研究

报道了S-胸腺嘧啶-L-半胱氨酸的FTIR光谱,及其固态、饱和液态的FT-Raman光谱.通过红外与拉曼光谱的结合,对其分子结构中各基团的振动情况进行了较为全面的解析;实验发现,该化合物在银胶上的最佳SERS的浓度为10-4mol·L-1,氨基峰在酸性条件下增强,羧基峰在碱性条件下增强,而其他基团峰随pH值的改变变化不大.依据SERS作用机理和规律,推测S-胸腺嘧啶-L-半胱氨酸在银胶表面的吸附是通过硫原子、羧基、氨基、胸腺嘧啶环和其中的氮原子与银原子配位,且胸腺嘧啶环是倾斜着与银纳米颗粒相吸附;该吸附模型的建立为拉曼光谱更深入研究PNA、多肽及其他生物分子提供了十分重要的信息和有益的参考.

FTIR, FT-Raman and surface enhanced Raman study of S-thyminyl-L-cysteine

The present paper reports the FT-infrared spectra and FT-Raman spectra of the S-thyminyl-L-cysteine. The optimal concentration of the S-thyminyl-L-cysteine on silver sol is 10(-4) mol L(-1). The interaction of S-thyminyl-L-cysteine with Ag nanoparticles was adsorbed by COO-, NH3+, S, and ring in the tilted way. Amino peak was enhanced in the acidic condition, carboxyl peak was enhanced in alkaline condition. Adsorption of S-thyminyl-L-cysteine on silver nanoparticles was mainly with carboxyl under the acidic condition and with amino under the alkaline condition. Other groups had no change at different pH. Establishment of this adsorption model provided important information and useful reference for further Raman spectra study of PNA, peptides and other biological molecules.