Optimizing gold nanoparticle seeding density on DNA origami

Abstract

DNA origami is a valuable technique in arranging nanoparticles into various geometries with a ∼100 nm footprint, high resolution, and experimental simplicity. Aligned nanoparticles, in addition to being used for photonics, can also be utilized to create thin metal wires with intricate and asymmetric junctions. Many factors affect the yield and density of nanoparticles attached to DNA origami structures, including the length and number of attachment sequences, the reaction ratio of nanoparticles to DNA origami, the hybridization temperature, and age of the solutions. This work investigates the alignment of closely packed 5 nm gold nanoparticles along thin DNA origami structures. Several reaction conditions, including hybridization time, magnesium ion concentration, ratio of nanoparticles to DNA origami, and age of the nanoparticle solution, were explored to optimize nanoparticle attachment density and spacing. Optimum ranges of conditions were identified, yielding new insights into high-density nanoparticle attachment to thin DNA origami structures, with potential for application in nanowire and nanoelectronics construction.