Conformational Changes of Uniformly Charged Polyelectrolyte Chains on the Surface of a Polarized Gold Nanoparticle: Molecular Dynamics Simulation and the Theory of a Gaussian Chain in a Field

The conformational changes of uniformly charged polypeptides adsorbed on the surface of a polarized gold nanoparticle are studied by means of molecular dynamics. The dependences of the average angular distributions and the radial density of polyelectrolyte atoms on the nanoparticle's surface are calculated. A gradual displacement of the polyelectrolyte units into the hemisphere with the opposite charge is observed on the surface of a polarized gold nanoparticle, along with pronounced rarefaction of the outer layer of the adsorbed chain relative to the inner one in this hemisphere of the nanoparticle. An analytical model is presented of the conformational changes in the polyelectrolyte, based on the equation for the dynamics of a Gaussian chain in the potential field of a polarized nanoparticle. A picture of the deformed edge of the polyelectrolyte and the radial angular dependences of its unit density on the surface of a polarized nanoparticle is constructed according to the analytical model.