Bilayer-Spanning DNA Nanopores with Voltage-Switching between Open and Closed State
Burns, Jonathan R
American Chemical Society
MetadataShow full item record
Seifert, A., Göpfrich, K., Burns, J. R., Fertig, N., Keyser, U., & Howorka, S. (2014). Bilayer-Spanning DNA Nanopores with Voltage-Switching between Open and Closed State. ACS Nano, 9 1117-1126. https://doi.org/10.1021/nn5039433
Membrane-spanning nanopores from folded DNA are a recent example of biomimetic man-made nanostructures which can open up applications in biosensing, drug delivery, and nanofluidics. In this report, we generate a DNA nanopore based on the archetypal six-helix-bundle architecture and systematically characterize it via singlechannel current recordings to address several fundamental scientific questions in this emerging field. We establish that the DNA pores exhibit two voltage-dependent conductance states. Low transmembrane voltages favor a stable high conductance level which corresponds to an unobstructed DNA pore. The expected inner width of the open channel is confirmed by measuring the conductance change as a function of poly(ethylene glycol) (PEG) size whereby smaller PEGs are assumed to enter the pore. PEG sizing also clarifies that the main ion conducting path runs through the membrane-spanning channel lumen as opposed to any proposed gap between the outer pore wall and the lipid bilayer. At higher voltages, the channel shows a main low-conductance state probably caused by electric field-induced changes of the DNA pore in its conformation or orientation. This voltage-dependent switching between the open and closed states is observed with planar lipid bilayer as well as bilayers mounted on glass nanopipettes. These findings settle a discrepancy between two previously published conductances. By systematically exploring a large space of parameters and answering key questions, our report lays the foundation for the development of new DNA nanopores for nanobiotechnology.
Nanopore, DNA nanotechnology, nanofluidics, PEG, single-molecule, bilayer membrane
The SH lab is supported by the Leverhulme Trust (RPG-170), UCL Chemistry, EPSRC (Institutional Sponsorship Award), the National Physical Laboratory, and Oxford Nanopore Technologies. KG acknowledges funding from the Winton Program of Physics for Sustainability, Gates Cambridge and the Oppenheimer Trust. UFK was supported by an ERC starting grant #261101.
European Research Council (261101)
External DOI: https://doi.org/10.1021/nn5039433
This record's URL: https://www.repository.cam.ac.uk/handle/1810/246666
ACS AuthorChoice License