Carbohydrate chemosensors based on stimuli-responsive complex emulsions

• Applicant: Dr. Lukas Zeininger
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Analytical Chemistry ; Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2017 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 331208670

The central theme of the postdoctorate will be the implementation of multi-phase complex emulsions with controllable and reconfigurable morphologies as novel chemoresponsive materials. A dynamic reconfiguration of emulsion droplet morphologies in response to environmental stimuli provide a unique potential for triggering a droplet reconfiguration and thus for creating an optical sensor readout by specific analytes, such as carbohydrates. By the addition of chromophores to the two immiscible phases of complex emulsions an inversion of droplet morphology will become visible. It is expected that slight morphology changes will suffice to dramatically influence the emission spectra through the ability of the complex emulsion droplets to selectively present and hide specific emission bands. This spectroscopic analysis of droplet morphologies will enable a quantifiable determination of droplet morphology with the potential to obtain an optical sensor readout. A controllable integration of tailor-designed molecular building blocks in such self-organized systems allow for the pursuit of new pathways for the chemosensing of carbohydrates. A dynamic covalent attachment of carbohydrates to tailor-designed boronic acid receptors are aimed to result in an optical response of the colored complex emulsion droplets. In principle, two signal chains of recognition, transduction and response are reasonable leading to an optical response of the complex emulsions and hence an optical sensor readout. The proposed independent pathways rely either on a change of the emulsion droplet fluorescence or an inversion of the droplet morphology by influencing the interfacial tensions. In both scenarios an optical response of multi-phase emulsion droplets will be characterized by emission spectroscopy and/or optical analysis of the droplet morphology. The implementation of the ability of the complex emulsion droplets to selectively invert morphology in dependence of the presence of a specific functionality will further pave the way for applications beyond chemosensors, such as a targeted release of drugs e.g. at tumours.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Timothy Manning Swager