Binding, Unbinding and Aggregation of Crescent-Shaped Particles on Tubular Membranes

Abstract

The binding of crescent-shaped nanoparticles (CNPs) on nanoscale tubular membranes is investigated through systematic coarse-grained molecular dynamics simulations of an implicit-solvent model. The CNPs adhere through their concave side to the outer surface of the tubular membrane. The binding/unbinding transitions are found to be irreversible, with the threshold binding energy, E b , being higher than that of the unbinding threshold, E u . Furthermore, the difference E b -E u increases with increasing either the CNP's arclength, L np , or curvature mismatch, m=R t /R np , where R np is the CNP's radius of curvature and R t is the tube's radius. We also investigated the arrangement of a CNP on the tube and found that for m smaller than a L np -dependent m*, the CNP lies perpendicularly to the tubule. However, for m<m*<1, the CNP is tilted with respect to the tubule's axis, with the tilt angle that increases with decreasing m. for m>1 (or m<m) and high L np , the NPs self-assemble into chains.