Self-assembly Of DNA On Au Nanoparticles: Molecular Dynamics Simulation

In DNA nanotechnology, use DNA which has good biological characteristics and nanoparticles on biological nano-manufacturing has great prospects, but also has enormous challenges. In the scientific experiments, using DNA and gold nanoparticles(AuNPs) has got the perfect crystal and has created the nanoscale devices, which brought DNA- AuNPs self-assembly research more positive revelation. The recent experimental studies on DNA- AuNPs self-assembly has broken the traditional, found that DNA and AuNPs have mutual adsorption phenomenon without chemical modification. With the rapid development of computer technology, the advanced computer technology is widely applied to the study of DNA- AuNPs self-assembly. Especially, molecular dynamics simulation speed up the study of DNA- AuNPs self-assembly.In this paper, based on the principle of molecular dynamics and applicate the Materials Studio molecular simulation software, we had studied the self-assembly of DNA and gold nanoparticles. System modeling were all created by all-atomic modeling, which can be clearly observed the chemical structure of the model and the structure change. Target system is composed by biological DNA, AuNps and solvent molecules. The DNA skeleton structure model was created by the model generator of 3D-DART, which contains 10 adenine DNA nucleotides, and use the Materials Studio software to repair it to be the perfect all atomic structure of DNA modeling. AuNPs was created by Materials Studio software, which was consisted of 201 gold atoms. The solvent is composed of water molecules. Using the COMPASS force field to describe the system.In the simulation, to study self-assembly of DNA and AuNPs, set the same conditions with the normal experimental environment to the analog system, and we found that the electrostatic interaction force between DNA and AuNPs is the dominant factor in DNA- AuNPs self-assembly system for DNA and AuNPs autonomous adsorption phenomena. We analyzes the equilibrium time, Mean Squrare Displacement(MSD), adsorption energy, et to study the effect of aqueous solution and temperature on the adsorption of DNA and AuNPs. We found that the aqueous solution is a "slavery" role in the DNA-AuNps self-assembly system, relative to the vacuum system. In addition, the temperature effect on DNA- AuNPs self-assembly system is obvious, and found that, under the temperature of 340 K, the adsorption effect of DNA and AuNPs is strongest and the stability is the best.