Research interests and projects
Control of self-assembly One of the biggest challenges in supramolecular chemistry is the control of self-assembly in order to obtain desired structures with desired properties. Nature can easily perform this with the help of templates, it builds functional molecules in response to external stimuli or environmental factors. Our projects aim at mimicking this adaptive behavior of biological systems, namely transfer molecular information stored in the interacting species to the functions of self-assembled architectures (receptors, sensors or catalysts). An example below illustrate how hydrogen bonds and a chloride template control self-assembly process (Chem. – Eur. J. 2013, 19, 3710-3714):
Molecular switches and artificial signal transduction are important topics for signal-processing at molecular level. We are looking at the molecular transformations in an unconventional way by combining molecular recognition events in one assembly to achieve such properties as reading, writing, memory, switching, logic operations and etc. We have developed a first cation molecular exchanger based on the cyclohexane ring. We have demostrated that binding of the zinc(II) cation to the bipyridine subunit induces the conformational switching of the crown ether subunits, which subsequently results in a release of the potassium cation. The release of the potassium cation can be detected by a cation sensor. (Org. Lett. 2018, 20 (19), 6211–6214)
Design of fluorescent sensors for analyte detection in water It is still a challenge to rationally design cheap and selective sensors for certain analytes functioning in a competitive aqueous medium. Though the problem is partially solved using substrate-selective proteins which are modified with fluorescent labels, less expensive sensors with novel selectivities are required. In this project we develop a new approach for the design of fluorescence sensors for a series of substrates (phosphates, carboxylates, amino acids and amines) that are operating in aqueous solution. Our approach is based on the screening of dynamic combinatorial libraries consisting of metal cations and newly designed ligands bearing fluorophores, and a consecutive evaluation of the components that are responsible for a selective detection of a particular guest. Chem. Eur. J. 2018, 24(7), 1500-1504
Nucleotide recognition by synthetic receptors. In this project, we study extensively non-covalent interactions between nucleobases and aromatic dyes to gain an understanding of the interaction strength, geometry of complexes and selectivity of the generated colorimetric or fluorometric response. Recently, we have developed a series of anthracene-based cyclophanes that are able to bind nucleoside triphosphates. Interestingly, cyclophanes show different binding modes and fluorescence responses. For example, binding of GTP is accomplished with a strong quenching of fluorescence, while binding of TTP results in an increase of the emission intensity.
2016-2018 Deutsche Forschungsgemeinschaft "Artificial receptors for perrhenate and pertechnetate"
2015-2017 Deutsche Forschungsgemeinschaft "Recognition and detection of orthophosphate"
2015 DFG International cooperation visits "Recognition of ATP by artificial receptors"
2012-2015 Deutsche Bundesstiftung Umwelt "Phosphat-Recycling durch selektive Ionenaustauscher"
2012-2015 Fonds der Chemischen Industrie "Identification of molecular sensors and recognition mechanisms from ligand-metal-analyte libraries"