Electric Field-Assisted Chemical Reactions and Sensing - NCCR MSE

Electric Field-Assisted Chemical Reactions and Sensing

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. 

Publications

Project Leader

Marcel Mayor

Lab

Mayor group @UniBas