DNA-assisted high-efficient purifying and encoding of gold nanotriangles

Combining the advantages of information encoding and function realization, DNA-conjugated nanomaterials have attracted great attention recently. As a typical anisotropic material, gold nano-triangle is of great value due to the sharp vertices. However, the yield of nano-triange is not high through current wet synthesis. In order to solve this problem, we propose a new strategy of shape selective separation of gold nano-triangles with the assist of thiol-DNA. The attachment of DNA to the surface of gold nanoparticles, on one hand, can stabilize the nanoparticles by shielding the direct contact between gold nanoparticles and solution environment. On the other hand, according to the particle shape, size and the surface charge density, gold nanoparticles have different mobilities in the electric field. As a result, gold nanoparticles can be separated by gel electrophoresis. The DNA-assist purification method gives a yield of above 80% of gold nano-triangles, which is also universal for the separation of nano-triangles with different sizes. More importantly, the surface-modified DNA can simultaneously separate and encode gold nano-triangles. By rational designing the DNA sequence, nano-triangles can be assembled on DNA origami and higher-order structures can be constructed.