Molecular Dynamics Simulation of Electrically Induced Conformational Changes of Polyampholytic Polypeptides on Gold Nanoparticle Surface

Abstract

Molecular dynamics has been employed to study conformational changes of polyampholytic polypeptides on the surface of a spherical gold nanoparticle at different surface charge densities, including the case of the presence of eosin Y anions adsorbed on polypeptide macrochains. Equilibrium conformations have been determined for polyampholytic polypeptides adsorbed of a spherical gold nanoparticle. Radial distributions of the concentration of atoms of polyampholytic polypeptides on the gold nanoparticle have been plotted with differentiation over the types of units at different surface charge densities. Corresponding distributions have also been obtained for dye anions adsorbed on polypeptide macrochains. The results obtained may be used for the development and modification of sensors with tunable conformational structures of macrochains, such as luminescent optical testers for the concentration of molecular oxygen (including singlet oxygen) and chemical sensors based on the effects of surface plasmon resonance and surface-enhanced Raman scattering.