Highly sensitive and selective chemical sensors: split-ring resonators with porous coordination frameworks

• Applicants: Dr. Andreas Schaate, since 2/2023; Professor Dr.-Ing. Stefan Zimmermann
• Subject Area: Measurement Systems
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 511400779

Today, chemical sensors can be found in almost all areas of our society, and important future topics, such as climate change, health, security and digitalization, require increasingly powerful chemical sensors. For the reliable detection of even smallest concentrations of certain compounds, chemical sensors with highest sensitivity and selectivity are needed. Therefore, we focus on a new sensing concept that combines the high sensitivity of split ring resonators to changes in dielectric material properties near the slit capacitor with nanoporous coordination polymers, which bind target molecules with very high specificity, thereby changing their electromagnetic properties. Thus, the project links two key topics in chemical sensor research: a) the development of highly sensitive transducers in form of split-ring resonators, which achieve highest sensitivity through new resonator topologies, such as coupled slit capacitors and three-dimensional structures, and new measurement concepts for continuous monitoring of the resonance frequency, such as differential arrangements, active circuit variants and special modulation and excitation methods; and b) the development of novel sensor materials in the form of nanoporous coordination polymers, which are based on the well-known class of metal-organic frameworks but have a significantly higher complexity and thus offer the target molecule an environment tailored exactly to its needs. This should lead to highest selectivity, which is otherwise only observed in biological recognition processes. Structural modelling und molecular dynamics simulations serve to find and to optimize such specifically tailored recognition geometries before the actual synthesis. The regioselective synthesis of such coordination polymers containing several different organic linker molecules is challenging and shall be carried out using newly developed synthesis strategies. In addition to fundamental research into new split-ring resonators suitable for chemical sensing and novel nanoporous coordination polymers as sensor materials, the project also aims to realize and experimentally characterize first sensors based on this concept for selected target molecules in the gas phase.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr. Peter Behrens, until 2/2023 (†)