STEM-EELS chemical imaging of lipid-coated and quantum dot containing silica nanoparticles; a novel diagnostic multimodality agent
M.M. van Schooneveld, O. Stephan, A. Gloter, A. Meijerink, W.J.M. Mulder, F.M.F. de Groot
Inorganic Chemistry & Catalysis, Debye Institute, Utrecht University, NL
Keywords: nanoscale characterization, STEM-EELS, spectromicroscopy, chemical imaging, nanoparticle, contrast agent, lipid-coated silica
Abstract:In summary, we recently made a novel multimodal contrast agent that consisted of a quantum dot containing silica particle and that was coated with a lipid monolayer. Characterization of the lipid layer on the small (35 nm) particles has been highly challenging. Here we have visualized the lipid layer around silica and determined its chemical and spatial composition by use of a high resolution STEM-EELS setup. This is a major step-forward compared to previous applied characterization methods for lipid layers (as for example NS TEM and DLS) around nanoparticles. To the best of our knowledge, this work is the first to report such direct visualization of diagnostically relevant lipid-coated contrast agents (and in fact of any kind of lipid-inorganic nanoparticle constructs). The biomedical, and especially the nanomedicine community, may strongly benefit from the use of this rich characterization method in their application of lipid-coated nanoparticles.