Formation of gold nanoparticle dimers on silicon by sacrificial DNA origami technique

To realize a nanogap-based single-molecule label-free detection device for surface-enhanced Raman scattering measurements, a new approach utilizing DNA origami (DO) as a sacrificial nano-structure is proposed. In this approach, gold nanoparticles (AuNPs) are precisely self-assembled to form a dimer structure on opposite faces of a rectangular DO structure. The AuNPs are then fixed on a silicon chip and the DO is selectively removed by UV irradiation. AuNP dimers were successfully fabricated with the proposed technique, demonstrating a simple and low-cost alternative to EB lithography approaches.