Asymmetric functionalization of nanoparticles based on thermally addressable DNA interconnects

A method for synthesizing nanoparticles asymmetrically functionalized with oligonucleotides was demonstrated. DNA linkers were used to connect oligonucleotide-modified gold nanoparticles to a larger oligo-nucleotide-modified SiO₂ particle to form satellite structure. The asymmetrically functionalized particles were used to build structures that are not easily accessible through the use of symmetrically functionalized particles. With the asymmetrically functionalized particles, a 10:1 molar ratio leads to complete formation of satellite structures with small amount of unbound 13 nm particles. Transmission Electron Microscopy (TEM) analysis showed that 533 nm gold particles support the formation of satellite structures and a small red-shift is associated with the formation of small aggregates. This method to functionalize very small nanoparticles with long oligoneucleotides is used to synthesize new nanostructures such as dimers, trimers, and one-dimensional arrays.