We report the surface modification of microscopic live multicellular nematodes Caenorhabtidis elegans with polyelec - trolyte multilayers ( pure and doped with 20 nm gold nanoparticles ) and the direct magnetic functionalization of nematodes with biocompatible magnetic nanoparticles. Magnetically functionalized “ironoxideclad” nematodes can be effectively separated and moved using an external magneticfield . The surface-functionalized nematodes preserve their viability and reproduction .