Binding, unbinding and aggregation of crescent-shaped nanoparticles on nanoscale tubular membranes


Using molecular dynamics simulations of a coarse-grained implicit solvent model, we investigate the binding of crescent-shaped nanoparticles (NPs) on tubular lipid membranes. The NPs adhere to the membrane through their concave side. We found that the binding/unbinding transition is first-order, with the threshold binding energy being higher than the unbinding threshold, and the energy barrier between the bound and unbound states at the transition that increases with increasing the NP's arclengthLnpor curvature mismatchμ=Rc/Rnp, whereRcandRnpare the radii of curvature of the tubular membrane and the NP, respectively. Furthermore, we found that the threshold binding energy increases with increasing eitherLnporμ. NPs with curvature larger than that of the tubule (μ> 1) lie perpendicularly to the tubule's axis. However, forμsmaller than a specific arclength-dependent mismatchμ*, the NPs are tilted with respect to the tubule's axis, with the tilt angle that increases with decreasingμ. We also investigated the self-assembly of the NPs on the tubule at relatively weak adhesion strength and found that forμ> 1 and high values ofLnp, the NPs self-assemble into linear chains, and lie side-by-side. Forμ<μ* and highLnp, the NPs also self-assemble into chains, while being tilted with respect to the tubule's axis.

Publication Title

Soft Matter