Periodic Reporting for period 1 - SENSiTRANS (Visible-light-activated transmembrane transport by photosensitized isomerization of stiff-stilbene based anion receptors)
Berichtszeitraum: 2023-09-01 bis 2025-08-31
The control of anion transport across membranes is essential for many biological processes. Several stimuli-responsive artificial anion transporters have been developed in recent years. Many of these transporters rely on light-stimulated isomerization, but a major limitation is their dependence on ultraviolet (UV) light, which limits applicability due to low tissue penetration and potential damage.
The objective of this fellowship was to develop a strategy to achieve the isomerization of stiff-stilbene anion transporters in lipid bilayers using visible light, a more practical alternative. The approach relied on a photosensitization strategy. The project combined the researcher’s expertise in organic synthesis with advanced training in supramolecular chemistry, photophysics and transmembrane transport studies at the host institution. The scientific pathway was structured into three research objectives: (1) to sensitize the isomerization of stiff-stilbene photoswitches in solution and lipid bilayers, (2) to achieve visible-light–activated anion transport across membranes, and (3) to explore strategies for active ion transport.
The objective of this fellowship was to develop a strategy to achieve the isomerization of stiff-stilbene anion transporters in lipid bilayers using visible light, a more practical alternative. The approach relied on a photosensitization strategy. The project combined the researcher’s expertise in organic synthesis with advanced training in supramolecular chemistry, photophysics and transmembrane transport studies at the host institution. The scientific pathway was structured into three research objectives: (1) to sensitize the isomerization of stiff-stilbene photoswitches in solution and lipid bilayers, (2) to achieve visible-light–activated anion transport across membranes, and (3) to explore strategies for active ion transport.
During the fellowship, the stiff-stilbene photoswitch was successfully isomerized via sensitization for the first time, both in solution and within lipid bilayers using visible-light–absorbing sensitizers. Sensitized isomerization within lipid membranes enabled the activation of a stiff-stilbene chloride transporter with visible light. This marked the achievement of the first two research objectives, demonstrating the feasibility of the concept.
In a further step, promising strategies were developed towards active transport, and a custom experimental setup for monitoring this process under irradiation was built in collaboration with the host institution’s technical workshops. Although the final goal of achieving active ion transport within lipid bilayers was not reached within the fellowship timeframe, all methodologies and tools required to achieve it are now in place and the host group is continuing the research.
In a further step, promising strategies were developed towards active transport, and a custom experimental setup for monitoring this process under irradiation was built in collaboration with the host institution’s technical workshops. Although the final goal of achieving active ion transport within lipid bilayers was not reached within the fellowship timeframe, all methodologies and tools required to achieve it are now in place and the host group is continuing the research.
The project advanced the state of the art in two ways. First, it demonstrated for the first time the sensitization of stiff-stilbene photoswitches using visible-light absorbing sensitizers. Second, it showed that the sensitized isomerization of stiff-stilbene can take place efficiently within the confined environment of a lipid bilayer, opening new avenues for the field of transmembrane anion transport. These advances are expected to impact both fundamental research in supramolecular chemistry and potential applications in areas such as energy conversion. The fellowship initiated a new research line at the host institution, ensuring long-term continuation of the work.