Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 36: Biopolymers and Biological Systems
CPP 36.6: Vortrag
Freitag, 29. Februar 2008, 11:45–12:00, C 264
Reversible photothermal dehybridization of DNA attached to gold nanoparticles — •Maximilian Reismann1, Jan Bretschneider2, Ulrich Simon2, and Gero von Plessen1 — 1I. Inst. of Physics (IA), RWTH Aachen University, Germany — 2Inst. for Inorganic Chemistry, RWTH Aachen University, Germany
Heat released from laser-irradiated metal nanoparticles can be applied to control biomolecules attached to the nanoparticles. Several studies have investigated destructive processes caused by nanoparticle-assisted photothermal heating, such as hyperthermia of malignant cells. In contrast, the photothermal control of non-destructive, i.e. reversible, biomolecular reaction processes has rarely been studied. Here we investigate the reversible photothermal control of the DNA dehybridization process. For this purpose, gold nanoparticle networks are synthesized using complementary single-stranded DNA as linker molecules. The well-known color change of such nanoparticle networks that occurs upon disassembly or assembly is applied to continuously monitor the state of the networks using optical spectroscopy. The DNA-nanoparticle network suspensions are heated by irradiation with focused c.w. laser light. This heating causes a disassembly of the networks, indicating the dehybridization (’melting’) of the DNA double strands. After laser irradiation, the networks reassemble, thus indicating the reversibility of the dehybridization process. It is shown that the DNA melting occurs predominantly within the 100 µm wide laser focus, where the intensity is highest, thus enabling a highly local control of the reaction.