DNA-functionalized nanoparticles have been suggested as a potent way to create various nanostructures. In this theoretical project we have investigated two models, a lattice model and an off-lattice model, that is, one modelling particles on a grid and one modelling freely moving particles. The models have been used to investigate behaviour of functionalized particles under different densities and temperatures, using the Monte Carlo algorithm to simulate Brownian motion. DNA strands are modelled on a coarse grained level with one length parameter and one energy parameter.We investigated nine realizations of functionalized particles, with strands aligned along the Cartesian coordinate axes. The model is parametrized using experimental results from literature. We show that the modelled particles assemble into ordered structures for temperatures between the boiling and freezing point of water. Particles assemble into four types of ordered structures; either expanding in one, two or three dimensions, or clusters. There is a particular interval of temperatures and densities at which these structures assemble. At temperatures not in the interval, particles assemble into disordered structures. The range of the temperature intervals decrease with increasing number of DNA strand attached to the particle. Lastly, we present a comparison of the two models and how realistic they are. We argue that both models are adequate for modelling single DNA strands, however if there are multiple DNA strands attached to a particle, the lattice model was found to yield realistic result only in some cases since it cannot represent orientational disordered structures.
|Uddannelser||Fysik, (Bachelor/kandidatuddannelse) Bachelor el. kandidat|
|Udgivelsesdato||25 jun. 2014|
|Vejledere||Ulf Rørbæk Pedersen|
- Monte Carlo