Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores
Layer-by-layer (LbL) deposition of polyelectrolytes and proteins within the cylindrical nanopores of anodic aluminum oxide (AAO) membranes was studied by optical waveguide spectroscopy (OWS). AAO has aligned cylindrical, nonintersecting pores with a defined pore diameter d0 and functions as a planar...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Beilstein-Institut
2012-06-01
|
| Series: | Beilstein Journal of Nanotechnology |
| Subjects: | |
| Online Access: | https://doi.org/10.3762/bjnano.3.54 |
| _version_ | 1818552006531350528 |
|---|---|
| author | Thomas D. Lazzara K. H. Aaron Lau Wolfgang Knoll Andreas Janshoff Claudia Steinem |
| author_facet | Thomas D. Lazzara K. H. Aaron Lau Wolfgang Knoll Andreas Janshoff Claudia Steinem |
| author_sort | Thomas D. Lazzara |
| collection | DOAJ |
| description | Layer-by-layer (LbL) deposition of polyelectrolytes and proteins within the cylindrical nanopores of anodic aluminum oxide (AAO) membranes was studied by optical waveguide spectroscopy (OWS). AAO has aligned cylindrical, nonintersecting pores with a defined pore diameter d0 and functions as a planar optical waveguide so as to monitor, in situ, the LbL process by OWS. The LbL deposition of globular proteins, i.e., avidin and biotinylated bovine serum albumin was compared with that of linear polyelectrolytes (linear-PEs), both species being of similar molecular weight. LbL deposition within the cylindrical AAO geometry for different pore diameters (d0 = 25–80 nm) for the various macromolecular species, showed that the multilayer film growth was inhibited at different maximum numbers of LbL steps (nmax). The value of nmax was greatest for linear-PEs, while proteins had a lower value. The cylindrical pore geometry imposes a physical limit to LbL growth such that nmax is strongly dependent on the overall internal structure of the LbL film. For all macromolecular species, deposition was inhibited in native AAO, having pores of d0 = 25–30 nm. Both, OWS and scanning electron microscopy showed that LbL growth in larger AAO pores (d0 > 25–30 nm) became inhibited when approaching a pore diameter of deff,n_max = 25–35 nm, a similar size to that of native AAO pores, with d0 = 25–30 nm. For a reasonable estimation of deff,n_max, the actual volume occupied by a macromolecular assembly must be taken into consideration. The results clearly show that electrostatic LbL allowed for compact macromolecular layers, whereas proteins formed loosely packed multilayers. |
| first_indexed | 2024-12-12T09:07:27Z |
| format | Article |
| id | doaj.art-afc58cea9c5046cca6cf3ab44c9b67cc |
| institution | Directory Open Access Journal |
| issn | 2190-4286 |
| language | English |
| last_indexed | 2024-12-12T09:07:27Z |
| publishDate | 2012-06-01 |
| publisher | Beilstein-Institut |
| record_format | Article |
| series | Beilstein Journal of Nanotechnology |
| spelling | doaj.art-afc58cea9c5046cca6cf3ab44c9b67cc2022-12-22T00:29:37ZengBeilstein-InstitutBeilstein Journal of Nanotechnology2190-42862012-06-013147548410.3762/bjnano.3.542190-4286-3-54Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanoporesThomas D. Lazzara0K. H. Aaron Lau1Wolfgang Knoll2Andreas Janshoff3Claudia Steinem4Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077 Göttingen, GermanyDepartment of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60202, USAAustrian Institute of Technology, Donau City Str. 1, 1220 Vienna, Austria,Institute of Physical Chemistry, Tammannstr. 6, 37077 Göttingen, GermanyInstitute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077 Göttingen, GermanyLayer-by-layer (LbL) deposition of polyelectrolytes and proteins within the cylindrical nanopores of anodic aluminum oxide (AAO) membranes was studied by optical waveguide spectroscopy (OWS). AAO has aligned cylindrical, nonintersecting pores with a defined pore diameter d0 and functions as a planar optical waveguide so as to monitor, in situ, the LbL process by OWS. The LbL deposition of globular proteins, i.e., avidin and biotinylated bovine serum albumin was compared with that of linear polyelectrolytes (linear-PEs), both species being of similar molecular weight. LbL deposition within the cylindrical AAO geometry for different pore diameters (d0 = 25–80 nm) for the various macromolecular species, showed that the multilayer film growth was inhibited at different maximum numbers of LbL steps (nmax). The value of nmax was greatest for linear-PEs, while proteins had a lower value. The cylindrical pore geometry imposes a physical limit to LbL growth such that nmax is strongly dependent on the overall internal structure of the LbL film. For all macromolecular species, deposition was inhibited in native AAO, having pores of d0 = 25–30 nm. Both, OWS and scanning electron microscopy showed that LbL growth in larger AAO pores (d0 > 25–30 nm) became inhibited when approaching a pore diameter of deff,n_max = 25–35 nm, a similar size to that of native AAO pores, with d0 = 25–30 nm. For a reasonable estimation of deff,n_max, the actual volume occupied by a macromolecular assembly must be taken into consideration. The results clearly show that electrostatic LbL allowed for compact macromolecular layers, whereas proteins formed loosely packed multilayers.https://doi.org/10.3762/bjnano.3.54avidin-biotindendrimersnanoporous substratesoptical lightmode waveguide spectroscopypolyelectrolytes |
| spellingShingle | Thomas D. Lazzara K. H. Aaron Lau Wolfgang Knoll Andreas Janshoff Claudia Steinem Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores Beilstein Journal of Nanotechnology avidin-biotin dendrimers nanoporous substrates optical lightmode waveguide spectroscopy polyelectrolytes |
| title | Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores |
| title_full | Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores |
| title_fullStr | Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores |
| title_full_unstemmed | Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores |
| title_short | Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores |
| title_sort | macromolecular shape and interactions in layer by layer assemblies within cylindrical nanopores |
| topic | avidin-biotin dendrimers nanoporous substrates optical lightmode waveguide spectroscopy polyelectrolytes |
| url | https://doi.org/10.3762/bjnano.3.54 |
| work_keys_str_mv | AT thomasdlazzara macromolecularshapeandinteractionsinlayerbylayerassemblieswithincylindricalnanopores AT khaaronlau macromolecularshapeandinteractionsinlayerbylayerassemblieswithincylindricalnanopores AT wolfgangknoll macromolecularshapeandinteractionsinlayerbylayerassemblieswithincylindricalnanopores AT andreasjanshoff macromolecularshapeandinteractionsinlayerbylayerassemblieswithincylindricalnanopores AT claudiasteinem macromolecularshapeandinteractionsinlayerbylayerassemblieswithincylindricalnanopores |