Field-dependent DNA mobility in 20 nm high nanoslits.
The transport behavior of lambda-DNA (48 kbp) in fused silica nanoslits is investigated upon application of electrical fields of different strengths. The slit dimensions are 20 nm in height, 3 microm in width, and 500 microm in length. With fields of 30 kV/m or below, the molecules move fluently through the slits, while at higher electrical fields, the DNA molecules move intermittently, resulting in a strongly reduced mobility. We propose that the behavior can be explained by mechanical and/or field-induced dielectrophoretic DNA trapping due to the surface roughness in the nanoslits. The observation of preferential pathways and trapping sites of the lambda-DNA molecules through the nanoslits supports this hypothesis and indicates that the classical viscous friction models to explain the DNA movement in nanoslits needs to be modified to include these effects. Preliminary experiments with the smaller XbaI-digested litmus-DNA (2.8 kbp) show that the behavior is size-dependent, suggesting that the high field electrophoresis in nanoslits can be used for DNA separation.
Salieb-Beugelaar
Georgette B
GB
BIOS/Lab-on-a-Chip Group, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. g.b.salieb-beugelaar@ewi.utwente.nl
Teapal
Juliane
J
Nieuwkasteele
Jan van
Jv
Wijnperlé
Daniël
D
Tegenfeldt
Jonas O
JO
Lisdat
Fred
F
van den Berg
Albert
A
Eijkel
Jan C T
JC
D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D013499:Surface Properties
D004247:DNA