Kegler Kati, Konieczny Martin, Dominguez-Espinosa Gustavo, Gutsche Christof, Salomo Matthias, Kremer Friedrich, Likos Christos N
Institute for Experimental Physics I, University of Leipzig, Linéestrasse 5, D-04103 Leipzig, Germany.
Phys Rev Lett. 2008 Mar 21;100(11):118302. doi: 10.1103/PhysRevLett.100.118302. Epub 2008 Mar 19.
Optical tweezers are employed to measure the forces of interaction within a single pair of DNA-grafted colloids, dependent on the molecular weight of the DNA chains, and the concentration and valence of the surrounding ionic medium. The resulting forces are short range and set in as the surface-to-surface distance between the colloidal cores reaches the value of the brush height. The measured force-distance relation is analyzed by means of a theoretical treatment that quantitatively describes the effects of compression of the chains on the surface of the opposite-lying colloid. Quantitative agreement with the experiment is obtained for all parameter combinations.
光镊被用于测量一对DNA接枝胶体颗粒之间的相互作用力，该力取决于DNA链的分子量、周围离子介质的浓度和价态。所产生的力是短程力，当胶体核心之间的表面到表面距离达到刷高值时就会出现。通过理论处理来分析测量得到的力-距离关系，该理论处理定量描述了链在相对胶体表面上的压缩效应。对于所有参数组合，都获得了与实验的定量一致性。
