Interactions of High Aspect Ratio Nanostructures and Biological Systems

• Main Author: Mumm, Florian
• Format: Doctoral Thesis
• Language: English
• Published: Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk 2010
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11960; http://nbn-resolving.de/urn:isbn:978-82-471-2483-3 (printed ver.); http://nbn-resolving.de/urn:isbn:978-82-471-2485-7 (electronic ver.)

As the length scale of basic biological processes coincides more and more with the length scale at which artificial nanostructures can be constructed, the interplay between those structures and biological systems becomes an increasingly promising field of research. This thesis is centred around high aspect ratio inorganic nanostructures, such as nanotubes and nanowires and how they can be made using biological structures, as well as how they can be used to manipulate biological systems. Two different approaches were taken: First, the very regular nanoporous structure, which makes up the spines of the bristle worm Aphrodita Aculeata (sea mouse) was used as a template to produce nanowires and nanotubes with a diameter of about 200 nm and a length of a few hundred microns. Nanowires made of nickel and copper were produced by electrodeposition and nanotubes made of aluminium oxide were produced by atomic layer deposition. Additionally, it was shown that the sea mouse spine based template was rigid enough to withstand a wide range of pHand temperatures, which should make it possible to grow nanostructures of a variety of materials by adopting fabrication procedures developed for membrane based nanoporous templates. In a second approach, vertically aligned arrays of copper oxide nanowires were grown in a catalyst-free thermal oxidation process on copper substrates. Methods of patterning were developed for the substrates and their nanowire decoration as well as a method for growing wires in large homogeneous arrays on inexpensive copper foils. Patterned copper substrates with and without a coating of nanowires were then used as the basis for a superhydrophobic droplet microfluidic system. Finally, the homogeneous arrays of vertically aligned copper oxide nanowires were integrated into photoresist microstructures made by traditional UV lithography to construct a transparent, cell friendly, compartmentalised system, which is intended to serve as a platform to transfect cells by impalement.