CiteULike: dchen Salomo http://www.citeulike.org/user/dchen/author/Salomo CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2767397 <i>Physical Review Letters, Vol. 100, No. 11. (2008)</i><br /><br />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. Polyelectrolyte-Compression Forces between Spherical DNA Brushes Kati Kegler Martin Konieczny Gustavo Espinosa Christof Gutsche Matthias Salomo Friedrich Kremer Christos Likos doi:10.1103/PhysRevLett.100.118302 Physical Review Letters, Vol. 100, No. 11. (2008) 2008-05-07T21:14:58-00:00 Physical Review Letters 100 11 APS biology colloids interaction opticaltweezer http://www.citeulike.org/user/dchen/article/2563086 <i>Physical Review Letters, Vol. 98, No. 5. (2007)</i><br /><br />Optical tweezers are employed to measure the forces of interaction between single DNA-grafted colloids. Parameters to be varied are the length of the DNA, the grafting density, and the ion concentration of the surrounding medium. From the measured force-separation dependence an interaction length at a given force is deduced. It shows in the mushroom regime a scaling with the grafting density which levels off for brushes. For the latter the transition from an osmotic to a salted brush can be traced in detail by varying the ion concentration in accordance with mean field theories. Forces of Interaction between DNA-Grafted Colloids: An Optical Tweezer Measurement K Kegler M Salomo F Kremer doi:10.1103/PhysRevLett.98.058304 Physical Review Letters, Vol. 98, No. 5. (2007) 2008-03-19T16:59:43-00:00 Physical Review Letters 98 5 APS 2007 biology colloids opticaltweezer