Berlin 2015 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 36: Plasmonics and Nanooptics

O 36.19: Poster

Dienstag, 17. März 2015, 18:15–21:00, Poster A

Calculation of photothermal heating in DNA-gold nanoparticle networks due to irradiation with laser light — Malte Linn, •Alexander Nedilko, and Gero von Plessen — Institute of Physics (IA), RWTH Aachen, Germany

Molecule metal-nanoparticle hybrid systems, such as DNA-gold nanoparticle (AuNP) networks, have attracted great interest because of their unique optical properties and their versatile chemical functionalities. Since DNA dehybridization is temperature-sensitive, the DNA-AuNP networks can be dissociated by thermal and photothermal heating. In this work, we calculate the temperature increase in DNA-AuNP networks induced by irradiation with c.w. laser light. To this end, we use generalized Mie theory to calculate the optical power absorbed by the individual nanoparticles in AuNP aggregates in water. By inserting the absorbed powers into finite-element calculations, the temporal and spatial changes of the temperature distribution within the AuNP aggregates and in their vicinity are computed. The maximal temperature in the AuNP aggregate is found to grow with aggregate size due to heat accumulation. While the irradiated AuNPs serve as heat sources, their individual temperature increases are only a few percent higher than those of the water regions between them, resulting in a relatively smooth temperature distribution in each aggregate.