Dresden 2020 – scientific programme
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BP: Fachverband Biologische Physik
BP 5: Bioimaging and Biospectroscopy I
BP 5.2: Talk
Monday, March 16, 2020, 15:30–15:45, HÜL 386
Trans-membrane Fluorescence Enhancement by Carbon Dots: Energy Transfer, Ionic Effects and pH Dependence — •Florian H. Huber1, Stefanie D. Pritzl1, Santanu Bhattacharyya1, Fernando Pschunder2, Maria Ana Huergo2, Theobald Lohmüller1, and Jochen Feldmann1 — 1Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstr. 10, 80539 Munich, Germany — 2INIFTA, Universidad Nacional de La Plata - CONICET, Sucursal 4 Casilla de Correo 16, 1900 La Plata, Argentina
Improved optical biosensors that are sensitive to the membrane potential of cells are highly desirable for imaging applications and microscopy studies of membrane systems. Here, we analyse how trans-membrane energy transfer between fluorescent carbon dots (CDs, size ~1.0 - 1.5 nm) and fluorescein labelled phospholipid molecules across the bilayer membrane of giant phospholipid vesicles is influence by ionic interactions and the pH. A system has been designed, where positively charged CDs and negatively charged fluorescein lipids co-localize across a bilayer membrane due to electrostatic attraction [1]. By performing absorbance, photoluminescence (PL), and fluorescence life time decay measurements, we find that ionic interactions do not only facilitate energy transfer, but also result in a PL enhancement of the dye, which is further adjustable by the pH of the vesicle suspension. [1] S.D. Pritzl, F. Pschunder, F. Ehrat, S. Bhattacharyya, T. Lohmueller, M. Huergo, J. Feldmann, Nano Letters, 19 (6), 3886-3891, 2019