The Role Radius of Curvature Plays in Thiolated Oligonucleotide Loading on Gold Nanoparticles

We show that by correlating the radius of curvature of spherical gold nanoparticles of varying sizes with their respective thiol-terminated oligonucleotide loading densities, a mathematical relationship can be derived for predicting the loading of oligonucleotides on anisotropic gold nanomaterials. This mathematical relationship was tested with gold nanorods (radius 17.5 nm, length 475 nm) where the measured number of oligonucleotides per rod (3330 +/- 110) was within experimental error of the predicted loading of 3244 oligonucleotides from the derivation. Additionally, we show that once gold nanoparticles reach a diameter of approximately 60 nm the local surface experienced by the oligonucleotide is highly similar to that of a planar surface.