Nano-assembly and welding of gold nanorods based on DNA origami and plasmon-induced laser irradiation

The bottom-up organization of noble metal nanostructures with nanometer-scale precision is an important goal in nanotechnology. Owing to their unique localized surface plasmon resonance, well-defined metal nanostructures arrays could be used to develop applications in nano-photonics, nano-plasmonics, and nano-electronics. This article proposes an alternative pathway of a controllable approach to assemble and weld together the gold nanostructures. As a typical plasmonic nanostructure, the gold nanorods (Au NRs) was synthesized by the classical seed-mediated growth method. Based on the recognition of biomolecules through complementary DNA hybridization, we used DNA origami strategy for controllable assembly of Au NRs. Rectangular DNA origami as a template can induce the geometrically assembled of Au NRs. We designed and fabricated tip-to-tip Au NRs dimers on the DNA templates. Then,the follow-up formation of nanojunctions between assembled tip-to-tip Au NRs dimers Au NRs was conducted by irradiating infrared femtosecond pulses laser. The ability to coupling plasmonic nanostructures by assembly and nano-welding could be fundamental to developing novel optical properties and ensuring materials.