Characteristics of gold nanowires and UV spectral changes by interaction between gold nanoparticles and DNA

Deoxyribonucleic acid (DNA) is ideal building blocks for conducting nanowires (NWs). DNA can obtain highly ordered electronic components for nanocircutitry and/or nanodevices because of its very flexible length controllability, nanometer-size diameter of about 2 nm and self-assembling properties. In this work, we used the method, which is the direct gold nanowires (AuNWs) formation by the electrostatic assembly of DNA with negative charges in phosphate groups and oxidized aniline-capped gold nanoparticles (AN-AuNPs) with positive charges in the solution phase. We investigated the assembly process between AN-AuNPs and DNA molecules by the change of incubation time and estimated the number of DNA molecules wrapping the AuNP surface by the size of AuNPs. Atomic force microscopy (AFM) images showed the interaction rate of AuNPs along DNA by the change of incubation time. AuNP number attached on the DNA molecules increased according to the increase of incubation time. Ultraviolet–visible (UV) spectroscopy measurement confirmed the assembly of AN-AuNPs and DNA by observing the formation of a novel absorption peak according to the absorption spectral change of AN-AuNPs and DNA.