A Raman detector for Field-Flow Fractionation for advanced in vitro characterization of Macromolecules

• Applicant: Professor Dr. Helmut Cölfen (†)
• Subject Area: Analytical Chemistry
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 424650380

This project aims to set up an on-line Raman detection system for asymmetrical-flow field flow fractionation (AF4). AF4 is a separation method for macromolecules, which also allows the determination of distributions of the diffusion coefficient resp. the hydrodynamic size over a range from 1 nm to 100 micro meters. Current detectors yield distributions of the molar mass and the relative sample concentrations. Also UV-Vis or fluorescence spectra for each component in complex mixtures can be measured. The proposed Raman detection introduces the possibility to gain information about the chemical nature of the sample. By this way, fractionated samples in complex mixtures could be distinguished solely by chemical groups without requiring any labelling as it is necessary for the distinction of many samples using UV-Vis and fluorescence detectors. Comparable methods to our proposal are only available under enormous financial expenses and with a strictly limited number of usable elution solvents. Even the single components of completely unknown samples could be fractionated and their chemical groups be identified in the Raman spectra. The Raman detector shall be tested with commercially available standard proteins and protein complexes with small molecules, nucleic acids or carbohydrates. Also, stabilizer molecules on core-shell nanoparticles shall be investigated as their chemical composition in situ should deliver valuable information for the optimization of nanoparticle synthesis, which cannot be obtained properly by existing methods.

• DFG Programme: Research Grants