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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 1: Gels, Polymers Networks and Elastomers I
CPP 1.6: Vortrag
Montag, 17. März 2025, 11:00–11:15, H34
Nanoscopic measurements of the water content in microgels using fluorescence lifetime imaging — •Dominik Wöll1, Alexandre Fürstenberg2, Jörg Enderlein3, Oleksii Nevskyi3, Sankar Jana1, Hannah Höche1, and Leon Trottenberg1 — 1RWTH Aachen University, Institute of Physical Chemistry, Aachen, Germany — 2University of Geneva, Department of Physical Chemistry and Department of Inorganic and Analytical Chemistry, Genf, Switzerland — 3Georg August University, 3rd Institute of Physics - Biophysics, Göttingen, Germany
The role of water molecules in the structure, function, and dynamics of (bio-)materials is significant, and thus, an estimation of the number of water molecules within different compartments is crucial. It has been demonstrated that the fluorescence of red emissive dyes is quenched in the presence of H2O, with the excited energy transferred to surrounding H2O molecules. Fluorescence lifetime imaging (FLIM) can thus be used to quantify the number of water molecules in proximity to the probing dye Atto 655, which was covalently embedded into microgels in the present study. Microgels represent an intriguing class of nanoparticles with considerable potential for applications in drug delivery and medicinal chemistry. We recorded FLIM images at varying H2O:D2O ratios, in both the swollen and collapsed states of the microgels at 22 ∘C and 40 ∘C, respectively. Stern-Volmer analysis enabled the calculation of the number of water molecules in the immediate vicinity of the dye molecule within the microgels at varying temperatures.
Keywords: Fluorescence Lifetime Imaging; Super-resolution Fluorescence Microscopy; Microgels; Water content; Fluorescence Quenching