In this transmission electron microscope image of a gold nanoparticle in a plant cell, you can just make out lines of atoms on the left side of the particle. The bar in the bottom left corner represents 2 nm.
Stem images of nanoparticles with kind permission of Dr Richard Haverkamps and Springer Science and Business Media (published in Journal of Nanoparticle Research (2007), 9:697-700, Pick your carats: nanoparticles of gold-silver-copper alloy produced in vivo by R.G Haverkamp, A.T Marshall and D. van Agterveld.)
