Slip-Coupled Electroosmosis and Electrophoresis Dictate DNA Translocation Speed in Solid-State Nanopores

Abstract

Controlling the DNA translocation speed is critical in nanopore sequencing, but remains rather challenging in practice, as attributable to a complex coupling between nanoscale fluidics and electrically mediated migration of DNA in a dynamically evolving manner. One important factor influencing the translocation speed is the DNA−liquid slippage stemming from the hydrophobic nature of the oligonucleotide, an aspect that has been widely ignored in the reported literature. In an effort to circumvent this conceptual deficit, here we first develop an analytical model to bring out the slip-mediated coupling between the electroosmosis and DNA−electrophoresis in a solid-state nanopore at low surface charge limits, ignoring the end effects. Subsequently, we compare these results with the numerical simulation data on electrokinetically modulated DNA translocation in such a nanopore, albeit of finite length with due accommodation of the end effects, connecting two end reservoirs by deploying a fully coupled Poisson−Nernst−Plank−Stokes flow model. Both the numerical and analytical results indicate that the DNA translocation speed is a linearly increasing function of the slip length, with more than fourfold increase being observed for a slip length as minimal as 0.5 nm as compared to the no-slip scenario. Considering specific strategies on demand for arresting high translocation speeds for accurate DNA sequencing, the above results establish a theoretical proposition for the same, premised on an analytical expression of the DNA-hydrophobicity modulated enhancement in the translocation speed for designing a nanopore-based sequencing platform�a paradigm that remained to be underemphasized thus far.

Layer-by-Layer Nanofluidic Membranes for Promoting Blue Energy Conversion

“…The use of fossil fuels has caused catastrophic climate change and irreversible environmental destruction. − There is a growing awareness of the necessity to develop alternative methods of energy generation in today’s world. However, alternatives should not only be easily accessible and affordably priced but also have zero impact on the environment. − Solar, wind, and water power as well as more portable options such as osmotic energy generation are just some of the alternative energy sources that have garnered the interest of scientists in recent years. − In addition, the growth of knowledge in the study of micronano structures has led to the development of more efficient techniques to create energy, the most significant of which is the creation of energy via water salinity variations using nanofluidic membranes. − …”