Conformation and confinement energy of interacting end-grafted molecules

Abstract

The conformation and confinement energy of flexible molecules grafted on a surface are considered in the framework of classical "random flight" model. Interactions among molecules are included in the analysis and closed form solutions are presented for two limiting cases where the core interaction is either very strong or very weak. The case of stiff molecules is also considered via a different approach where their thermally-induced bending deformations, as well as interactions, have been taken into account. We will demonstrate that, under seemingly identical conditions, the behavior of stiff molecules is quite different from that of flexible ones. Predictions obtained here agree with various experimental observations on the grafting density of single- and double-stranded DNAs on a gold surface. © 2012 Imperial College Press.