Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 24: Posters: DNA/RNA and Related Enzymes
BP 24.8: Poster
Donnerstag, 29. März 2012, 17:30–19:30, Poster A
Thermal and photothermal dissociation of DNA-gold nanoparticle networks of different sizes — •Malte Linn1, Anne Buchkremer2, Ulrich Simon2, and Gero von Plessen1 — 1Inst. of Physics (IA), RWTH Aachen University, Germany — 2Inst. of Inorganic Chemistry, RWTH Aachen University, Germany
The functionalization of gold nanoparticles (AuNPs) with DNA allows the construction of DNA-AuNP networks, which have the ability to act as both optical sensors and actuators. By using optical extinction spectroscopy (OES), it is possible to monitor the state of the networks, since the mutual electromagnetic coupling of individual particles inside each network leads to a red shift of the plasmon peak position with respect to single particles. Since DNA dehybridization is temperature-sensitive, network dissociation can be triggered either by mere conventional heating or by introducing additional photothermal heating via irradiation with cw laser light. In this work, we tailor the size of the DNA-AuNP networks by varying the ratio of complementarily functionalized AuNPs. The size dependence of the optical and chemical properties of the networks is investigated and quantified by means of OES and dynamic light scattering. These properties depend on the network size, because larger networks involve a greater number of AuNPs and DNA bonds. The influence of additional photothermal heating on the dissociation temperature associated with each network size is also investigated.