The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion
The behavior of nanoparticles under nanofluidic confinement depends strongly on their distance to the confining walls; however, a measurement in which the gap distance is varied is challenging. Here, we present a versatile setup for investigating the behavior of nanoparticles as a function of the ga...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Beilstein-Institut
2018-01-01
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| Series: | Beilstein Journal of Nanotechnology |
| Subjects: | |
| Online Access: | https://doi.org/10.3762/bjnano.9.30 |
| _version_ | 1818507127783686144 |
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| author | Stefan Fringes Felix Holzner Armin W. Knoll |
| author_facet | Stefan Fringes Felix Holzner Armin W. Knoll |
| author_sort | Stefan Fringes |
| collection | DOAJ |
| description | The behavior of nanoparticles under nanofluidic confinement depends strongly on their distance to the confining walls; however, a measurement in which the gap distance is varied is challenging. Here, we present a versatile setup for investigating the behavior of nanoparticles as a function of the gap distance, which is controlled to the nanometer. The setup is designed as an open system that operates with a small amount of dispersion of ≈20 μL, permits the use of coated and patterned samples and allows high-numerical-aperture microscopy access. Using the tool, we measure the vertical position (termed height) and the lateral diffusion of 60 nm, charged, Au nanospheres as a function of confinement between a glass surface and a polymer surface. Interferometric scattering detection provides an effective particle illumination time of less than 30 μs, which results in lateral and vertical position detection accuracy ≈10 nm for diffusing particles. We found the height of the particles to be consistently above that of the gap center, corresponding to a higher charge on the polymer substrate. In terms of diffusion, we found a strong monotonic decay of the diffusion constant with decreasing gap distance. This result cannot be explained by hydrodynamic effects, including the asymmetric vertical position of the particles in the gap. Instead we attribute it to an electroviscous effect. For strong confinement of less than 120 nm gap distance, we detect the onset of subdiffusion, which can be correlated to the motion of the particles along high-gap-distance paths. |
| first_indexed | 2024-12-10T22:14:20Z |
| format | Article |
| id | doaj.art-fa589e52c5f142adaf93168c1343d72c |
| institution | Directory Open Access Journal |
| issn | 2190-4286 |
| language | English |
| last_indexed | 2024-12-10T22:14:20Z |
| publishDate | 2018-01-01 |
| publisher | Beilstein-Institut |
| record_format | Article |
| series | Beilstein Journal of Nanotechnology |
| spelling | doaj.art-fa589e52c5f142adaf93168c1343d72c2022-12-22T01:31:31ZengBeilstein-InstitutBeilstein Journal of Nanotechnology2190-42862018-01-019130131010.3762/bjnano.9.302190-4286-9-30The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusionStefan Fringes0Felix Holzner1Armin W. Knoll2IBM Research - Zurich, Säumerstr. 4, 8803 Rüschlikon, SwitzerlandIBM Research - Zurich, Säumerstr. 4, 8803 Rüschlikon, SwitzerlandIBM Research - Zurich, Säumerstr. 4, 8803 Rüschlikon, SwitzerlandThe behavior of nanoparticles under nanofluidic confinement depends strongly on their distance to the confining walls; however, a measurement in which the gap distance is varied is challenging. Here, we present a versatile setup for investigating the behavior of nanoparticles as a function of the gap distance, which is controlled to the nanometer. The setup is designed as an open system that operates with a small amount of dispersion of ≈20 μL, permits the use of coated and patterned samples and allows high-numerical-aperture microscopy access. Using the tool, we measure the vertical position (termed height) and the lateral diffusion of 60 nm, charged, Au nanospheres as a function of confinement between a glass surface and a polymer surface. Interferometric scattering detection provides an effective particle illumination time of less than 30 μs, which results in lateral and vertical position detection accuracy ≈10 nm for diffusing particles. We found the height of the particles to be consistently above that of the gap center, corresponding to a higher charge on the polymer substrate. In terms of diffusion, we found a strong monotonic decay of the diffusion constant with decreasing gap distance. This result cannot be explained by hydrodynamic effects, including the asymmetric vertical position of the particles in the gap. Instead we attribute it to an electroviscous effect. For strong confinement of less than 120 nm gap distance, we detect the onset of subdiffusion, which can be correlated to the motion of the particles along high-gap-distance paths.https://doi.org/10.3762/bjnano.9.30Au nanospheresconfinementnanofluidicssubdiffusion |
| spellingShingle | Stefan Fringes Felix Holzner Armin W. Knoll The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion Beilstein Journal of Nanotechnology Au nanospheres confinement nanofluidics subdiffusion |
| title | The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion |
| title_full | The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion |
| title_fullStr | The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion |
| title_full_unstemmed | The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion |
| title_short | The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion |
| title_sort | nanofluidic confinement apparatus studying confinement dependent nanoparticle behavior and diffusion |
| topic | Au nanospheres confinement nanofluidics subdiffusion |
| url | https://doi.org/10.3762/bjnano.9.30 |
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