Nanopores as Solid-State Approach to Interlinked Reaction Compartments

  • Figure caption: Schematic representation of a nanopore for probing electron transport (A) or molecule-photon interactions (e.g. for light-harvesting applications) by using a semi-transparent top or bottom electrode (B). Nanopores are interconnected via oxide-embedded microchannels to enable ionic exchange in electrochemical studies (C). Influence of light and electrochemical environment on molecular transport can further be studied simultaneously (D). Lower row shows 2x2 nanopore arrays and electrical and electrochemical interconnects. Every nanopore can be addressed electrically, optically, electrochemically or a combination thereof.
    Figure caption: Schematic representation of a nanopore for probing electron transport (A) or molecule-photon interactions (e.g. for light-harvesting applications) by using a semi-transparent top or bottom electrode (B). Nanopores are interconnected via oxide-embedded microchannels to enable ionic exchange in electrochemical studies (C). Influence of light and electrochemical environment on molecular transport can further be studied simultaneously (D). Lower row shows 2x2 nanopore arrays and electrical and electrochemical interconnects. Every nanopore can be addressed electrically, optically, electrochemically or a combination thereof.

The chemical and physical processes enabling the transformation of matter in living systems is regulated by complex feedback loops. Such tightly cross-regulated processes enable highly complex reaction cascades as well as transport and exchange mechanisms that have not yet been achieved in synthetic systems. The project „Nanopores as Solid-State Approach to Interlinked Reaction Compartments" strives to simulate isolated feedback mechanisms to investigate the underlying regulation mechanisms in detail and to identify the parameters governing the system.

To fabricate such interlinked reaction compartments, we aim at fabricating nanopore devices based on a solid-state approach using top-down fabrication techniques. Self-assembled monolayers (SAMs) of functional molecular building blocks are physically separated but remain addressable by electrical, optical or electrochemical means. The SAMs are highly oriented which enables correlations between chemical structure and electronic as well as ionic transport properties in single-molecular junctions to be studied. 

Preliminary studies will allow us to mimic a biological response and to investigate isolated feedback mechanisms in detail. Additionally, from a materials point of view, the resulting oligomers may be interesting. Their physical properties are length-dependent and, thanks to a feedback mechanism, their length-distribution may become tunable by specific parameters dictated by the system, leading to a new size-control approach with wide potential applications in material science. Modular systems can easily be expanded with additional functionalities. For example redox-­dependent chromophores that will facilitate the investigation of the systems dynamics as it can be investigated by optical microscopy.

The project is not only geared towards investigating feedback mechanisms across vesicle membranes but also towards integrating vesicles as molecular factories. With such vesicles, molecular devices enabling photo-induced charge separation across the vesicle membrane will be studied. In a later stage of the project, we envisage electrochemical interconnecting of different functionalized vesicles to build up gradients of chemical potentials. 

Articles

Y. Aeschi, S. Drayss-Orth, M. Valášek, F. Raps, D. Häussinger, M. MayorAssembly of [2]rotaxanes in water“ Eur. J. Org. Chem. (2017). [Link]
L. O. Herrmann, A. Olziersky, C. Gruber, G. Puebla-Hellmann, U. Drechsler, T. von Arx, K. Venkatesan, L. Novotny, E. Lörtscher, G. Puebla-HellmanFabrication of NEMS actuated plasmonic antenna platform for the study of optical forces and field enhancements in hot-spots“ Asia Communications and Photonics Conference 2016, AS4B.2 (2016). [Link]
G. Puebla-Hellmann, M. Mayor, E. Lörtscher, G. Puebla-HellmanFunctional Nanopores: A Solid-state Concept for Artificial Reaction Compartments and Molecular Factories“ Chimia 6, 432 (2016). [Link]
C. M. Gruber, L. O. Herrmann, A. Olziersky, G. Puebla-Hellman, U. Drechsler, T. von Arx, M. Koch, Z. J. Lapin, K. Venkatesan, L. Novotna, E. Lortscher “Fabrication of bow-tie antennas with mechanically tunable gap sizes below 5 nm for single-molecule emission and Raman scattering“ IEEE Nano, 20 (2015). [Link]
G. Puebla-HellmanM. Mayor, E. Lortscher “Ultraflat nanopores for wafer-scale molecular-electronic applications“ IEEE Nano, 1197 (2015). [Link]

Who works with whom?

Prof Marcel Mayor of the University of Basel leads this project and works with Gabriel Puebla-Hellman (postdoc) and Marco Masiero (PhD). The fabrication and characterization of the nanopore devices is done at IBM Research - Zurich under the supervision of Dr. Emanuel Lörtscher.

Group

Read more about the Mayor-Group here

Collaborations

Tailor-­made molecular modules for physical and physico-­che-mical experiments will be designed and synthesized in collaboration with projects led by Wolfgang Meier, Thomas Pfohl, Roderick Lim, Michel Calame, Dimitrios Fotiadis, Stefan Matile and Francesco Stellacci.

Nanoscopically Controlled Templates for the Assembly of Molecular Modules and the Control of Reaction Pathways by Urs Dürig and Keith Carroll (Surface patterning using Electron-beam Lithography). 

Smart Stimuli-responsive polymer membranes by Cornelia G. Palivan and Viktoria Mikhalevich (membrane fabrication).