Spatially-resolved EELS analysis of antibody distribution on biofunctionalized magnetic nanoparticles.

Spatially resolved electron energy loss spectroscopy (SR-EELS) using scanning transmission electron microscope (STEM) allows the identification and determination of the spatial distribution of the components/elements of immuno-functionalized core-shell superparamagnetic magnetite nanoparticles. Here, we report that SR-EELS measurements allow the direct identification and study of the biological moieties (protein G and anti-HRP antibody) in complex bionanocarriers of relevance for biomedical applications. Our findings show that the biomacromolecules are located on specific areas on the nanoparticles' surface. In addition, efficiency of this functionalization was evaluated by means of biochemical techniques.