Macromolecular Gates in Nanofluidic Channels

Research Project, 2016 – 2020

The combination of soft matter and nanotechnology has raised many new scientific questions and opens up for several important applications. This interdisciplinary project deals with questions such as: How do macromolecules behave in confined space? How can diffusive transport of e.g. proteins through a macromolecular network be made selective, as it is in biological systems? Can one make artificial nanoscale gates and control their permeability individually? Is it possible to entrap single molecules in volumes as small as one attoliter by confining them in between such gates?

In summary, the project aims to construct gates based on macromolecules attached to the solid walls of nanofluidic channels. Polymer brushes will form the basis for the gates, but other molecules such as receptors (antibodies or aptamers) will also be incorporated to make “passive” gates that allow selected targets to pass based on molecular recognition. So called responsive polymers will be used in order to prepare “active” gates that truly open and close by local changes in the physiochemical environment, induced by nanoscale electrodes. Primarily, resistive heating or electrochemical control of pH on the nanoscale will be utilized. As a starting point, recently fabricated nanopores (vertical channels) in multi-layered thin films of metals and insulators will be used. The nanopores also offer the possibility to perform optical sensing by excitation of surface plasmons in order to study the macromolecules inside or to detect transport events through the nanogates. In the long term, multiple gates with individual control will be incorporated in defined networks of nanofluidic channels.

The proposed research will provide insights into the fundamental behavior of macromolecules. The project will also have a high impact in other research fields such as biophysics and analytical chemistry through synergetic effects. Future applications in biotechnology and lab-on-a-chip devices are envisioned.