Electroosmotic flow velocity in DNA modified nanochannels
Loading...
Date
2019-10-01
Authors
Li, Jun
Li, Dongqing
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Electroosmotic flow (EOF) is systematically investigated in DNA grafted hard PDMS (h-PDMS) channels with size ranging from 50 nm to 2.5 μm by using the current-slope method. The effects of the DNA types, the incubation time in the process of surface modification, and the pH value, ionic concentration of electrolyte solutions, and the UV (ultraviolet) illumination on the velocity of electroosmotic flow are experimentally studied. It is found that the DNA type and the incubation time of DNAs affect the grafting density and the surface charge on the channel walls, thus influencing the EOF velocity. In the DNA modified channels, the pH effects on EOF velocity become less prominent compared with that in the pristine channels. On the contrary, UV illumination can increase the EOF velocity significantly in the DNA modified channels, whereas takes unapparent effects on EOF velocity in the pristine channels. The effects of ionic concentration on EOF are also studied in this paper. It is observed that EOF velocity is dependent on the channel size when the ionic concentration is low even without overlapped electric double layer (EDL) and is essentially independent of the channel size when the ionic concentration is high. Furthermore, with high ionic concentration and thin EDL, the EOF velocity can be enhanced by the coated DNA brushes on the channel surface.
Description
The final publication is available at Elsevier via https://doi.org/10.1016/j.jcis.2019.06.002. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license
http://creativecommons.org/licenses/by-nc-nd/4.0/
Keywords
electroosmotic flow, nanochannel, surface modification, electric double layer