Ce^4＋水解切断5′—AMP，3′—AMP和CAMP的原位增强拉曼光谱研究

Study on in situ Surface Enhanced Raman Scattering (SERS) of 5' - AMP, 3' - AMP and CAMP Hydrolysis by Ce4+ Ion

首次用原位增强拉曼光谱技术研究了Ce4+水解切断核苷酸的过程.实验表明在粗糙化的银表面可以得到5'-AMP,3'-AMP和CAMP明显增强的拉曼光谱,Ce4+水解切断5'-AMP时在2 895cm-1和2 950 cm-1处分别出现CH2的振动峰;3'-AMP中原有CH2振动峰,当它的磷酸酯键被Ce4+水解切断时,这些峰则明显减弱,甚至消失.把Ce4+水解切断CAMP过程的原位拉曼光谱与5'-AMP和3'-AMP同Ce4+反应以后的拉曼光谱相比较,推测Ce4+断裂CAMP时,首先切断CAMP中的一个磷酸酯键,生成5'-AMP和3'-AMP,随着反应的进行Ce4+再逐渐断裂5'-AMP和3'-AMP的磷酸酯键,生成最终产物腺苷.

Surface enhanced Raman scattering (SERS) spectra of nucleotide hydrolysis mediated by Ce4+ ion are reported. The experimental results demonstrated that excellent SERS spectra of 5' - AMP, 3' - AMP and CAMP could be obtained on rough silver surface. New additional peaks at 2895 cm(-1) and 2950 cm(-1) were observed after 5' - AMP hydrolysis by Ce4+. These signals were all assigned to the vibration of CH2. These signals were also observed with 3' - AMP but they were either weakened or disappeared after hydrolysis of the 3' - AMP by Ce4+. Comparing the in, situ SERS spectra of CAMP hydrolysis by Ce4+ ion with those of 5' AMP, 3' - AMP reaction with Ce4+ ion, we conclude that in the beginning Ce4+ ion only cleaves one phosphate ester, giving a mixture of 5' - AMP and 3' - AMP, with the reaction proceeds, another phosphate ester is also hydrolysis to yield adenosine.