Shifting molecular localization by plasmonic coupling in a single-molecule mirage

Over the last decade, two fields have dominated the attention of sub-diffraction photonics research: plasmonics and fluorescence nanoscopy. Nanoscopy based on single-molecule localization offers a practical way to explore plasmonic interactions with nanometre resolution. However, this seemingly straightforward technique may retrieve false positional information. Here, we make use of the DNA origami technique to both control a nanometric separation between emitters and a gold nanoparticle, and as a platform for super-resolution imaging based on single-molecule localization. This enables a quantitative comparison between the position retrieved from single-molecule localization, the true position of the emitter and full-field simulations. We demonstrate that plasmonic coupling leads to shifted molecular localizations of up to 30 nm: a single-molecule mirage. The near-field interaction of single emitters and plasmonic structures can alter the perceived physical location of the emitter. Here, Raab et al . use DNA origami and far-field super-resolution microscopy to quantitatively evaluate this localization offset for gold nanoparticles.