Scanning electron microscope observation of heterogeneous three-dimensional nanoparticle arrays using DNA

DNA oligonucleotides are considered to be as a useful tool for fabricating complex structures on a nanometer scale because of their selective reactivity. Herein, we describe a fabrication technique for heterogeneous three-dimensional nanoparticle arrays composed of gold nanoparticles of two different sizes linked by thiol-synthesized DNA oligonucleotides. Each size of the gold nanoparticles was encapsulated by complementary DNA oligonucleotides. DNA hybridization occurs upon their mixing, resulting in the construction of a three-dimensional nanostructure. Scanning electron microscope (SEM) observation and UV spectroscopy were performed to confirm the construction of the nanostructure. This fabrication technique will be crucial for the advancement of nanotechnology in the next ten years.