Conformational Nature of DNAGrafted Chains on Spherical Gold Nanoparticles
Jack F. Douglas, Fernando Vargas-Lara
We investigate the conformational state of a simple, coarsegrained molecular model for singlestranded DNA chains (ss-DNA) grafted onto spherical symmetric gold nanoparticles (NPs) and of the grafted layer as a whole by molecular dynamic simulations. In particular, we compare the radius of gyration (Rg) of an individual grafted chain to its value in solution and we use pathintegration to estimate the change delta Rh of the hydrodynamic radius of ssDNAgrafted NPs (Rh) from the hydrodynamic radius of the bare gold NP core (R = 5:0 nm) for a range of grafted chains (N), chain lengths (L), and persistence lengths (lp) relevant to experimental studies of these NPs. We find the ssDNA chain size is not greatly perturbed from its free solution value so that the molecular cartoon of a brushlike layer involving highly extended ssDNA chains is an unrealistic model of the interfacial structure of ssDNAgrafted NPs under the solution conditions normally investigated.
AIP Conference Proceedings
gold nanoparticle, single-stranded DNA, chain grafting, conformation of grafted chain layer, radius of gyration, hydrodynamic radius