dc.creatorTeschke, O
dc.creatorDouglas, RA
dc.creatorProlla, TA
dc.date1997
dc.dateAPR 14
dc.date2014-12-16T11:34:37Z
dc.date2015-11-26T18:02:12Z
dc.date2014-12-16T11:34:37Z
dc.date2015-11-26T18:02:12Z
dc.date.accessioned2018-03-29T00:43:51Z
dc.date.available2018-03-29T00:43:51Z
dc.identifierApplied Physics Letters. Amer Inst Physics, v. 70, n. 15, n. 1977, n. 1979, 1997.
dc.identifier0003-6951
dc.identifierWOS:A1997WT57300020
dc.identifier10.1063/1.118797
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/76569
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/76569
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/76569
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1292163
dc.descriptionIn many attempts to image biomolecules like deoxyribonucleic acid with the atomic force microscope, the apparent width of the molecules exceeds the expected width as obtained by x-ray diffraction. This increase in size was explained by a geometrical tip convolution, but the increased width seems to persist despite improvements to the tip. Experimental evidence is shown that part of this increase is due to the liquid drag force when molecules are imaged under liquid. The liquid drag force is calculated using standard fluid dynamics where the tip motion in the liquid is modeled by the relative motion of a cylinder through a constant velocity fluid. The Reynold's number for the experimental configuration is smaller than 1, characterizing a laminar flow and the calculated drag force is 80 pN, which is in agreement with the experimentally measured force for ethanol and relative tip velocity of 100 mu m/s. Both the viscous drag force and the apparent width increase may be modeled by a v(k) dependence, where v is the sample velocity relative to the tip, and k is a constant independent of the liquid and the tip-sample geometry and is equal to 0.53. An apparent molecular width increase of similar to 30 nm for a similar to 2 nm diam molecule for a 150 mu m/s scanning velocity was observed. (C) 1997 American Institute of Physics.
dc.description70
dc.description15
dc.description1977
dc.description1979
dc.languageen
dc.publisherAmer Inst Physics
dc.publisherWoodbury
dc.relationApplied Physics Letters
dc.relationAppl. Phys. Lett.
dc.rightsaberto
dc.sourceWeb of Science
dc.subjectDna-molecules
dc.subjectSurfaces
dc.subjectWater
dc.subjectAir
dc.titleViscous drag effect on imaging of linearized plasmid deoxyribonucleic acid in liquid medium with the atomic force microscope
dc.typeArtículos de revistas


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