A new radiolabeling method for commercial Ag0 nanopowder with 110mAg for sensitive nanoparticle detection in complex media

Nanoparticle (NP) tracking in complex media is still a challenge since NP concentrations are expected to be low compared to elemental background levels as it can be found in environmental matrices. This study presents a new method for radiolabeling of commercial silver nanopowder (Ag-0-NPs, dp < 100 nm) with Ag-110m radionuclides (t(1/2) = 249.9 days) that provide an adequate time frame for particle detection, localization, and tracking under various experimental conditions. The radiolabeling procedure insures high efficiency, stability, and consistency of important particle properties such as size and morphology. Detection of Ag-0-NP in concentrations as low as 125 ng kg(-1) could be reached. For the first time, an appropriate tool for life-cycle studies of commercial Ag-0-NPs is provided without changing chemical composition of thematerial. This is of great importance e.g., for research in the field of nanotoxicology.