Dresden 2009 – wissenschaftliches Programm
CPP 16.7: Poster
Dienstag, 24. März 2009, 14:00–16:30, P3
Photothermal imaging of gold particles in living cells — •Nils Neubauer1, Carsten Stüber2, Josef Käs2, and Frank Cichos1 — 1Molecular Nanophotonics Group, University of Leipzig, Linnéstraße 5, 04103 Leipzig — 2Soft Matter Physics Group, University of Leipzig, Linnéstraße 5, 04103 Leipzig
Many biochemical processes in living cells depend strongly on temperature. Local heating might provide a versatile tool for manipulating such processes. Nevertheless a strongly localized heat generation is required for this purpose. This can be achieved by optical heating of single nanometer sized gold particles. Optical excitation of the plasmon resonance of the gold nanoparticle allows precise control of heat release. Furthermore the thermal field around a single particle is strongly localized. Here we present a study on the following two questions: How do the particles distribute within a cell and secondly, how do they affect the cell metabolism? Gold nanoparticles have been visualized in living cells by photothermal heterodyne detection. By absorbing laser light and the subsequent conversion into heat, these particles locally induce a change in refractive index of the surrounding media, which can be probed with a confocal laser scanning setup. This technique offers both imaging and studying the local effect of heat release by the gold nanoparticles. In the first experiments fibroblasts were used to study the distribution of gold nanoparticles with 40 nm down to 10 nm in size. While the 40 nm particles do not penetrate the membrane and adhere around the cell, the 10 nm particles enter and accumulate inside the cell.