LAUSR

The ability to track interfacial dynamics of a single nanoparticle at the solution-solid interface is crucial for understanding physical, chemical, and biological processes, but it remains a challenge. Here, we demonstrated a plasmonic imaging technique that can track unlabeled nanoparticles at the solution-solid interface with high spatial and temporal resolutions. This technique is based on particle-induced interferometric scattering of surface plasmonic wave, which results in a high vertical sensitivity. Using this ability, we tracked the trajectories of single nanoparticle interacting with a surface, measured the hydrodynamically hindered diffusion of nanoparticles and revealed the surface chemistry dependent behavior of nanoparticles at the interface. The application for tracking the formation of membranes from lipid vesicle was demonstrated, indicating the potential for investigating a broad range of nano-objects at interfaces in a complex environment.