文献类型：期刊文献

英文题名：Structure of the Complex Monolayer of Gemini Surfactant and DNA at the Air/Water Interface

作者：Chen, Qibin[3,4];Kang, Xueli[3,4];Li, Rong[3,4];Du, Xuezhong[1,2];Shang, Yazhuo[3,4];Liu, Honglai[3,4];Hu, Ying[3,4]

机构：[1]Nanjing Univ, State Key Lab Coordinat Chem, Minist Educ, Key Lab Mesoscop Chem, Nanjing 210093, Jiangsu, Peoples R China;[2]Nanjing Univ, Sch Chem & Chem Engn, Nanjing 210093, Jiangsu, Peoples R China;[3]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[4]E China Univ Sci & Technol, Dept Chem, Shanghai 200237, Peoples R China

年份：2012

卷号：28

期号：7

起止页码：3429

外文期刊名：LANGMUIR

收录：;EI(收录号：20121614957468);WOS:【SCI-EXPANDED(收录号:WOS:000300466200013)】；

基金：This work is supported by the National Natural Science Foundation of China (No. 20806025, 21173079), the 111 Project of Ministry of Education of China (Grant B08021), and the Fundamental Research Funds for the Central Universities of China.

语种：英文

外文关键词：Dyes - Isotherms - Langmuir Blodgett films - Cationic surfactants - DNA - Gene therapy - Circular dichroism spectroscopy - Atomic force microscopy - Dichroism - Fourier transform infrared spectroscopy

摘要：The properties of the complex monolayers composed of cationic gemini surfactants, [C18H37(CH3)(2)N+-(CH2)(s)-N+ (CH3)(2)C18H37],2Br(-) (18-s-18 with s = 3, 4, 6, 8, 10 and 12), and ds-DNA or ss-DNA at the air/water interface were in situ studied by the surface pressure area per molecule (pi-A) isotherm measurement and the infrared reflection absorption spectroscopy (IRRAS). The corresponding Langmuir-Blodgett (LB) films were also investigated by the atomic force microscopy (AFM), the Fourier transform infrared spectroscopy (FT-IR), and the circular dichroism spectroscopy (CD). The pi-A isotherms and AFM images reveal that the spacer of gemini surfactant has a significant effect on the surface properties of the complex monolayers. As s <= 6, the gemini/ds-DNA complex monolayers can both laterally and normally aggregate to form fibril structures with heights of 2.0-7.0 nm and widths of from several tens to similar to 300 nm. As s > 6, they can laterally condense to form the platform structure with about 1.4 nm height. Nevertheless, FT-IR, IRRAS, and CD spectra, as well as AFM images, suggest that DNA retains its double-stranded character when complexed. This is very important and meaningful for gene therapy because it is crucial to maintain the extracellular genes undamaged to obtain a high transfection efficiency. In addition, when s <= 6, the gemini/ds-DNA complex monolayers can experience a transition of DNA molecule from the double-stranded helical structure to a typical psi-phase with a supramolecular chiral order.