DNA origami based assembly of gold nanoparticle dimers for SERS detection

摘要

Plasmonic sensors are extremely promising candidates for label-free single molecule analysis but require exquisite control over the physical arrangement of metallic nanostructures. We employ self-assembly based on the DNA origami technique for accurate positioning of individual 40 nm gold nanoparticles with gaps of 3.3 ± 1 nm. This is probed through far field scattering measurements on individual dimers. This plasmonic coupling allows us to use surface enhanced Raman scattering (SERS) to detect a small number of dye molecules as well as short single-stranded DNA oligonucleotides in the vicinity of the dimers. This demonstrates that DNA origami is a powerful tool with great potential for a wide variety of biosensing and single-molecule applications.