Nonequilibrium Capture Rates Induce Protein Accumulation and Enhanced Adsorption to Solid-State Nanopores
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Single molecule capturing of analytes using an electrically biased nanopore is the fundamental mechanism in which nearly all nanopore experiments are conducted. With pore dimensions being on the order of a single molecule, the spatial zone of sensing only contains approximately a zeptoliter of volume. As a result, nanopores offer high precision sensing within the pore but provide little to no information about the analytes outside the pore. In this study, we use capture frequency and rate balance theory to predict and study the accumulation of proteins at the entrance to the pore. Protein accumulation is found to have positive attributes such as capture rate enhancement over time but can additionally lead to negative effects such as long-term blockages typically attributed to protein adsorption on the surface of the pore. Working with the folded and unfolded states of the protein domain PDZ2 from SAP97, we show that applying short (e.g., 3–25 s in duration) positive voltage pulses, rather than a constant voltage, can prevent long-term current blockades (i.e., adsorption events). By showing that the concentration of proteins around the pore can be controlled in real time using modified voltage protocols, new experiments can be explored which study the role of concentration on single molecular kinetics including protein aggregation, folding, and protein binding.
Date Issued
2014-11-26
Date Acceptance
2014-11-14
Citation
ACS Nano, 2014, 8 (12), pp.12238-12249
ISSN
1936-086X
Publisher
American Chemical Society
Start Page
12238
End Page
12249
Journal / Book Title
ACS Nano
Volume
8
Issue
12
Copyright Statement
© 2014 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work seehttps://dx.doi.org/10.1021/nn5062645
Identifier
http://pubs.acs.org/doi/abs/10.1021/nn5062645
Publisher URL