Regensburg 2004 – wissenschaftliches Programm
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SYLS: Life Sciences on the Nanometer Scale - Physics Meets Biology
SYLS 3: Symposium "Life Sciences on the Nanometer Scale - Physics Meets Biology"
SYLS 3.19: Poster
Mittwoch, 10. März 2004, 16:00–18:30, B
Carbon nanotube-assisted microwave absorption of gold nanoparticles across bacterial membranes — •Jose Rojas-Chapana1, Miguel Correa-Duarte1, Neli Sobal1, Krzysztof Kempa2, and Michael Giersig1 — 1Caesar Research Center, Ludwig-Erhard Allee 2, 53175 Bonn — 2Boston College, Boston, MA, USA
Acidothiobacillus ferrooxidans an acid tolerant bacterium was used as a tool to study intracellular incorporation and storage of gold nanoparticles (GN) induced by carbon nanotubes (CNTs). The microwave (MW) irradiation induced an electrostatic charge in the CNTs. Under this condition all the single CNTs work as an electric dipole. The addition of a small concentration of CNTs to a medium containing both bacteria and GN, and subsequent MW-irradiation leads to intracellular transport of gold without altering the viability of bacterial cells. As is shown by the transmission electron microscopy (TEM) examination, CNT tip heads are very close to the cell wall of bacteria. This CNTs-cell electrical contact is a prerequisite for the onset of temporary channels. One of the possible mechanisms during the MW-irradiation is a local electrical dipole induced in CNTs which leads to cell-wall destabilization, having the dimension of the CNTs tip heads (ca.30 nm diameter), which in turn act as a channel for the transport of gold. The occurrence of this phenomenon, as documented by TEM images, constitutes the most important factor facilitating MW-induced transport of GN across the cells.