| 1. |
- Beck, Marc, et al.
(författare)
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Fabrication and characterization of a molecular adhesive layer for micro- and nanofabricated electrochemical electrodes
- 2002
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Ingår i: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
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Konferensbidrag (refereegranskat)abstract
- When making nanoelectrodes for applications in liquid cells it is plausible that the less noble metal layer may be negatively affected, i.e. it will be etched away leading to very unstable conditions during operation. Here we describe a dry method to produce such a molecular layer consisting of mercaptopropyltriethoxysilane (MPTS) making it possible to controllable and reproducibly form a covalently bound monolayer of MPTS to the SiO2 surface. From Photoelectron Spectroscopy measurements we could conclude that the layer thickness corresponds to a monolayer. We have electrochemically characterized such electrodes by cyclic voltammetry. Furthermore, we have successfully patterned such layers at both micro- and nanometer scale showing the possibilities to fabricate chemically selective and active areas that may be used in various applications
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| 2. |
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| 3. |
- Bunk, Richard, et al.
(författare)
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Actomyosin motility on nanostructured surfaces
- 2003
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Ingår i: Biochemical and Biophysical Research Communications. - 1090-2104. ; 301:3, s. 783-788
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Tidskriftsartikel (refereegranskat)abstract
- We have here, for the first time, used nanofabrication techniques to reproduce aspects of the ordered actomyosin arrangement in a muscle cell. The adsorption of functional heavy meromyosin (HMM) to five different resist polymers was first assessed. One group of resists (MRL-6000.1XP and ZEP-520) consistently exhibited high quality motility of actin filaments after incubation with HMM. A second group (PMMA-200, PMMA-950, and MRI-9030) generally gave low quality of motility with only few smoothly moving filaments. Based on these findings electron beam lithography was applied to a bi-layer resist system with PMMA-950 on top of MRL-6000.1XP. Grooves (100-200 nm wide) in the PMMA layer were created to expose the MRL-6000.1XP surface for adsorption of HMM and guidance of actin filament motility. This guidance was quite efficient allowing no U-turns of the filaments and approximately 20 times higher density of moving filaments in the grooves than on the surrounding PMMA.
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| 4. |
- Bunk, Richard
(författare)
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Creation of a Nanometer-Scale Toolbox for Molecular Motor Transport-Circuits
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents studies of molecular motors in interaction with nm-scale structures, as well as the development of a set of tools that can be used for the construction of custom-designed nano-transportation systems. In our studies, we have used the latest nanoscale technology and combined this with advanced results from chemistry and biomedical sciences. We have succeeded in transferring biomolecules from their natural habitat to an artificial environment created on a silicon-chip. The molecules - motor proteins myosin and actin - were maintained in their fully functional state by controlling the surface morphology and chemistry of the chip environment with nm-scale precision. These proteins are nanomachines, capable of transforming chemical energy into mechanical work. Our work has been concentrated on the introduction and development of a toolbox concept. A set of nm-scale tools, or components, have been defined and created, each with their unique basic transport function. The custom-designed components have been constructed as independent building blocks that can be combined into any circuit design of for example motor-driven micro-laboratories. The designing can be performed without detailed knowledge of the underlying mechanisms, e.g. lithography or motor protein biochemistry. To some extent, the concept resembles that of micro-electronics. The key components in the toolbox have been constructed of molecular monolayers and lithographic resist. We have found that monolayers of trimethylchlorosilane can be used to make conventional semiconductor materials, such as silicon, biocompatible. Furthermore, we have created a three-dimensional resist structure on the surface of a silicon-chip, that have been used to guide the mechanical motion developed by the motor proteins. With this novel design we have reduced the degrees of freedom for the proteins so that the effective guidance precision has increased successively from millimeter-, to micrometer- and eventually nanometer scale. Principally, electron-beam lithography has been used for the fabrication of the samples, although nano-imprint lithography has also been demonstrated as a powerful tool for parallel massive production on a commercial scale. In a series of experiments we have fine-tuned and characterized the properties of each toolbox component. Tools have been developed to capture and stream the molecular motors, reroute them and to analyze them. We have also demonstrated how cargo can be attached to the filaments, and performed successful experiments with chemically-linked quantum dots.
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| 5. |
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| 6. |
- Bunk, Richard, et al.
(författare)
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Guiding molecular motors with nano-imprinted structures
- 2005
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922. ; 44:5A, s. 3337-3340
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Tidskriftsartikel (refereegranskat)abstract
- This work, for the first time, demonstrates that nano-imprinted samples, with 100 nm wide polymer lines, can act as guides for molecular motors consisting of motor proteins actin and myosin. The motor protein function was characterized using fluorescence microscopy and compared to actomyosin motility on non-structured nitrocellulose surfaces. Our results open for further use of the nano-imprint technique in the production of disposable chips for bio-nanotechnological applications and miniaturized biological test systems. We discuss how the nano-imprinted motor protein assay system may be optimized and also how it compares to previously tested assay systems involving low-resolution UV-lithography and low throughput but high-resolution electron beam lithography.
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| 7. |
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| 8. |
- Bunk, Richard, et al.
(författare)
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Guiding motor-propelled molecules with nanoscale precision through silanized bi-channel structures
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 16:6, s. 710-717
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Tidskriftsartikel (refereegranskat)abstract
- We report on the design and fabrication of a channel structure for high precision guidance and achieving excellent confinement properties for motor-propelled molecular shuttles. The techniques used to manufacture the channel structure are mainly e-beam lithography and selective monolayer functionalization. The structure consists of two lateral layers of concentric channels on a SiO2 surface made biocompatible with the molecular motors. The quality and advantages of the design are demonstrated by experiments using the motor proteins actin and myosin. The special channel geometry leads to stable biochemical conditions with full motor protein functionality. ATP is sufficiently supplied to all parts of the structure by dedicated service channels, as is the venting of ADP and P-i (inorganic phosphorus). Channels of different widths (100-700 nm) and shapes are fabricated and measurements made on them.
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| 9. |
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| 10. |
- Bunk, Richard, et al.
(författare)
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Towards a 'nano-traffic' system powered by molecular motors
- 2003
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 67-8, s. 899-904
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we reconstructed in vitro the behavior of two motor proteins-myosin and actin-responsible for the mechanical action of muscle cells. By transferring this in vivo system to an artificial environment, we were able to study the interaction between the proteins in more detail, as well as investigating the central mechanism of force production. Nm-patterning by e-beam lithography (EBL) could restore parts of the in vivo protein order, essential for potential nanotechnological applications. Much work was put into establishing the necessary compatibility between the biological and nano-lithographical processes. A range of EBL-resists were tested for protein compatibility. One particular kind (MRL-6000.1XP) supported good actin filament motility, while another (PMMA-950) behaved in the opposite way. Taking advantage of these findings, nm-sized lines were created in a double-layer structure of the two resists. The lines were found to act as binding sites for myosin, and as rectifying guides for the linearized motion of actin filaments. Velocities around 5 mum/s were measured. (C) 2003 Elsevier Science B.V. All rights reserved.
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