Current Fluctuations in Nanopores Reveal the Polymer-Wall Adsorption Potential
| Autor: | Nicole E. Weckman, Douwe Jan Bonthuis, Stuart F. Knowles, Vincent J. Y. Lim, Ulrich F. Keyser, Alice L. Thorneywork |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
General Physics and Astronomy Ionic bonding FOS: Physical sciences 02 engineering and technology Condensed Matter - Soft Condensed Matter 010402 general chemistry 01 natural sciences Noise (electronics) Adsorption Physics - Biological Physics chemistry.chemical_classification Quantitative Biology::Biomolecules Polymer Polymer adsorption Quartz crystal microbalance 021001 nanoscience & nanotechnology 0104 chemical sciences Characterization (materials science) Condensed Matter::Soft Condensed Matter Nanopore chemistry Chemical physics Biological Physics (physics.bio-ph) Soft Condensed Matter (cond-mat.soft) 0210 nano-technology |
| Zdroj: | Physical review letters. 127(13) |
| ISSN: | 1079-7114 |
| Popis: | Modification of surface properties by polymer adsorption is a widely used technique to tune interactions in molecular experiments such as nanopore sensing. Here, we investigate how the ionic current noise through solid-state nanopores reflects the adsorption of short, neutral polymers to the pore surface. The power spectral density of the noise shows a characteristic change upon adsorption of polymer, the magnitude of which is strongly dependent on both polymer length and salt concentration. In particular, for short polymers at low salt concentrations no change is observed, despite verification of comparable adsorption in these systems using quartz crystal microbalance measurements. We propose that the characteristic noise is generated by the movement of polymers on and off the surface and perform simulations to assess the feasibility of this model. Excellent agreement with experimental data is obtained using physically motivated simulation parameters, providing deep insight into the shape of the adsorption potential and underlying processes. This paves the way towards using noise spectral analysis for in situ characterisation of functionalised nanopores. Comment: 5 pages (excluding references), 4 figures |
| Databáze: | OpenAIRE |
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