TEM tomography of microgels with gold nanoparticles

Hybrid systems consisting of microgels and gold nanoparticles (AuNPs) were investigated applying TEM tomography on a dried sample. The sample holder was tilted in a range of ± 72° with respect to the electron beam. The tomography images show the localization of the AuNP inside the microgel and even allow the visualization of the microgel core. Both, the shell containing the nanoparticles, and the core are deformed due to the adsorption on the carbon coated copper grid and the subsequent drying, during which the dense core adopts the shape of a “biconvex lens”, surrounded by a nanoparticle “envelope”.