DFT and SERS Study of N-15 Full-Labeled Adenine Adsorption on Silver and Gold Surfaces
DFT and SERS Study of N-15 Full-Labeled Adenine Adsorption on Silver and Gold Surfaces
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N-15 全标记腺嘌呤在银和金表面吸附的 DFT 和 SERS 研究
DOI：
10.1021/acs.jpcc.7b00818
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发表时间：
2017
影响因子：
3.7
通讯作者：
Huang Qing
中科院分区：
文献类型：
--
作者：
Yao Guohua;Zhai Zhimin;Zhong Jie;Huang Qing
核酸碱基在纳米颗粒金属表面的吸附近年来在生物和纳米技术领域受到广泛关注，但腺嘌呤如何吸附到金属表面仍然是一个有争议的问题。由于腺嘌呤中的氮在分子识别和相互作用中起着重要作用，与氮相关的光谱特征是吸附构型分析的关键。为此，我们采用B3LYP/6-311+G(d,p)水平的密度泛函理论(DFT)计算来模拟吸附构型，同时从实验和理论上检验了吸附在银和金纳米粒子表面的15N全标记腺嘌呤相应的表面增强拉曼光谱(SERS)。 SERS 谱带的光谱位置、强度和同位素位移的一致性表明，吸附在银或金表面上的腺嘌呤具有相同的吸附构型，其中 N7H 腺嘌呤通过 N3 和 N9 位点与 Ag4+/Au4+ 簇相互作用。因此，这项研究不仅可以为腺嘌呤与贵金属的相互作用提供新的见解，而且还证明了基于应用于同位素分子的 DFT 和 SERS 工具相结合的有效方法来解决核酸碱基在金属表面上的吸附问题。
Adsorption of nucleic acid bases on metal surface of nanoparticles has received much attention recently in bio- and nanotechnology, while it still remains a controversial problem in how adenine is adsorbed onto the metal surface. As the nitrogen in adenine plays an important role in the molecular recognition and interaction, the spectral feature related to the nitrogen is the key to analysis of the adsorption configurations. For this purpose, we employed density functional theory (DFT) calculations at B3LYP/6-311+G(d,p) level for the simulation of adsorption configurations, and in the meantime we checked the corresponding surface enhanced Raman spectroscopy (SERS) of15N fully labeled adenine adsorbed on the surfaces of silver and gold nanoparticles both experimentally and theoretically. The agreement of spectral positions, intensities, and isotopic shifts of the SERS bands, suggests that adenine adsorbed on either silver or gold surface takes the same adsorption configuration in which N7H adenine interacts with Ag4+/Au4+cluster through both N3 and N9 sites. This study therefore may not only provide new insight into the interaction of adenine with noble metals but also have demonstrated the effective approach based on the combination of DFT and SERS tools applied in isotopic molecules to the issue of adsorption of nucleic acid bases onto metal surfaces in general.