  We form single-electron transistors from individual chemically-synthesized
gold nanoparticles, 5-15 nm in diameter, with monolayers of organic molecules
serving as tunnel barriers. These devices allow us to measure the discrete
electronic energy levels of individual gold nanoparticles that are, by virtue
of chemical synthesis, well-defined in their composition, size and shape. We
show that the nanoparticles are non-magnetic and have spectra in good accord
with random-matrix-theory predictions taking into account strong spin-orbit
coupling.
