Quantification of hydrophobic interactions between single alkane molecules

化学系的实验物理化学计划支持杜克大学化学系的Boris Akhremitchev教授的研究。 Akhremitchev和他的学生将通过应用原子力显微镜和单分子力光谱学的新方法来研究单分子水平上的疏水相互作用。 这些测量将在纳米尺度上探测水环境中单个疏水分子之间的相互作用。 相互作用的烃分子将通过柔性亲水性连接体拴系到基底和探针上，以避免表面伪影。 这些实验将探索疏水相互作用对相互作用物种的大小和温度的依赖性。 这项研究将测试“去湿假说”，这表明，对于纳米尺寸的疏水溶质的水密度耗尽发生在溶质的表面。 拟议工作的具体目标包括测量和数据分析程序的发展，以准确地确定激活势垒宽度和不同大小的碳氢化合物之间的单分子相互作用的解离速率。这些研究旨在阐明我们在分子水平上对水环境中非极性分子间相互作用的疏水性的理解。 疏水相互作用对于许多生物和技术过程是至关重要的，并且在生物化学、生物医学和生物技术中具有根本重要性。 该研究项目将培训本科生和研究生，以及少数民族高中生，在纳米科学的基础研究。 Akhremitchev还将开发一门研究生水平的课程，涉及原子力显微镜和单分子力光谱学的技术方面和当代应用。

The Experimental Physical Chemistry program of the Division of Chemistry supports the research of Professor Boris Akhremitchev of the Department of Chemistry, Duke University. Akhremitchev and his students will investigate hydrophobic interactions at a single-molecule level by applying new approaches to atomic force microscopy and single-molecule force spectroscopy. These measurements will probe the interactions between individual hydrophobic molecules in aqueous environments on a nanometer scale. Interacting hydrocarbon molecules will be tethered to a substrate and probe via flexible hydrophilic linkers to avoid surface artifacts. These experiments will explore the dependence of hydrophobic interactions on the size of interacting species and on temperature. This research will test the "dewetting hypothesis," which suggests that for nanometer size hydrophobic solutes a depletion of water density occurs at the surface of the solute. Specific goals of the proposed work include the development of measurement and data analysis procedures to accurately determine activation barrier widths and dissociation rates of single-molecule interactions between hydrocarbons of different sizes. These studies aim to clarify our molecular level understanding of hydrophobicity in interactions between non-polar molecules in aqueous environments. Hydrophobic interactions are critical for many biological and technological processes and are of fundamental importance in biochemistry, biomedicine, and biotechnology. The research project will train undergraduates and graduate students, as well as minority high school students, in fundamental research in nanoscience. Akhremitchev also will develop a graduate level course in the technical aspects and contemporary applications of atomic force microscopy and single-molecule force spectroscopy.