Dresden 2011 – scientific programme

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BP: Fachverband Biologische Physik

BP 32: Posters: Other Topics in Biological Physics

BP 32.2: Poster

Thursday, March 17, 2011, 17:15–20:00, P3

Time resolved optical Measurements of Dye-Functionalized Quantum-Dots with Polymer-Coating: A step towards Multiplex Sensing Systems — •Sebastian Friede, Tobias Niebling, Faheem Amin, Wolfgang J. Parak, and Wolfram Heimbrodt — Fachbereich Physik und WZMW, Philipps Universität Marburg, Renthof 5, 35037 Marburg.

Modern biological sensing systems are using the spectral diversity of fluorescence dyes mostly. An alternative concept for realizing e.g. ion-sensitive sensor systems is the multiplex sensing approach in combination with temporal resolved spectroscopy. Therefore two dyes are bound to a nanoparticle: an ion sensitive dye and a reference-dye. Avoiding spectral overlaps of the reference dyes and the sensing dyes, spectral similar dyes are chosen as reference-dyes for all sensing systems. In order to determine the concentrations of multiple species of ions there is a need to distinguish the luminescence intensities of the used dyes, specially those of the reference dyes. To do so, the fluorescence lifetimes of the reference dyes can be modified by using different kinds of nanoparticles. Bearing in mind the Stokes-shift, semiconductor-quantum dots with the right-tuned emission wavelenght can act as energy-donors for fluorophores and so enhance the fluorophore fluorescence-lifetimes. In contrast, the fluorescence lifetime of dye functionalized gold-cored hybrid systems is affected differently. We could show that a clear distinction of the reference dyes of the different sensor-particles is possible by measuring the fluorescence lifetimes of the dyes.