Self-Assembly and Molecular Recognition of Adenine- and Thymine-Functionalized Nucleolipids in the Mixed Monolayers and Thymine-Functionalized Nucleolipids on Aqueous Melamine at the Air鈥揥ater Interfa

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• 作者：Yanyan Xin ; Xianming Kong ; Xianfeng Zhang ; Zhongpeng Lv ; Xuezhong Du
• 刊名：Langmuir
• 出版年：2012
• 出版时间：July 31, 2012
• 年：2012
• 卷：28
• 期：30
• 页码：11153-11163
• 全文大小：554K
• 年卷期：v.28,no.30(July 31, 2012)
• ISSN：1520-5827

文摘

Self-assembly and molecular recognition of the monolayers composed of an equimolar mixture of adenine- and thymine-functionalized nucleolipids at the air鈥搘ater interface have been investigated in detail using surface pressure鈥搈olecular area isotherms and in situ infrared reflection absorption spectroscopy (IRRAS). Prior to molecular recognition, the adenine moieties in the monolayer were almost oriented on an end-on mode through 蟺-stacking and hydrogen bonding interactions, and the C鈥揅鈥揅 planes of the alkyl chains were preferentially oriented perpendicular to the water surface, while the thymine moieties in the monolayer were involved in hydrogen bonding almost with a flat-on orientation. On aqueous subphases containing complementary bases, no significant molecular recognition was observed for the monolayers of individual nucleolipids. In the monolayer of equimolar mixture, molecular recognition occurred between the adenine and thymine moieties through hydrogen bonding probably with the development of cyclic structures of adenine鈥搕hymine鈥揳denine鈥搕hymine quartets. Although molecular recognition between the monolayer of thymine-functionalized nucleolipids and aqueous melamine took place through triple hydrogen bonds, no melamine binding to the monolayer of equimolar mixture was observed, which reflects the formation of the quartets in the mixed monolayers at the air鈥搘ater interface. FTIR and small-angle X-ray diffraction (XRD) results of the corresponding Langmuir鈥揃lodgett films support the hydrogen bonding recognition and molecular orientation.