The video-rate imaging of sub-10 nm plasmonic nanoparticles in a cellular medium free of background scattering†

Plasmonic nanoparticles (e.g., gold, silver) have attracted much attention for biological sensing and imaging as promising nanoprobes. Practical biomedical applications demand small gold nanoparticles (Au NPs) with a comparable size to quantum dots and fluorescent proteins. Very small nanoparticles with a size below the Rayleigh limit (usually
An absorption modulated scattering microscopy technique that allows for the imaging of sub-10 nm gold nanoparticles within a cellular scattering medium is presented.