Birgit Hagenhoff oral presentation (SN3-Wed2-2-2)
DETECTION OF NANOPARTICLES IN LUNG TISSUE BY TIME-OF-FLIGHT SECONDARY ION MASS SPECTROMETRY
1 Tascon GmbH - University of Siegen, Mendelstraße 17, 48149 Münster, Germany
2 Tascon GmbH, Mendelstr. 17, 48149 Münster, Germany
The localized detection of nanoparticles in biological tissues is an essential part of nanotoxicological research and therefore an important necessity for nanosafety. In general, the detection is carried out using techniques such as fluorescence microscopy, scanning electron microscopy-/ EDX or laser ablation ICP-MS. However, these techniques have limitations in lateral resolution, or need markers for unambiguous detection of particles.
Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) allows detection of the chemical composition without the use of markers at lateral resolutions below 100 nm. The aim of this study was to demonstrate the equivalence of ToF-SIMS data with data of fluorescence microscopy (standard technique for bioanalysts) and thus highlight its suitability for nanotoxicological analyses. For this purpose, a tissue section of a rat lung was treated with fluorescent nanoparticles. The distribution of the fluorescent particles was analyzed with the help of the established method of fluorescence microscopy.
ToF-SIMS Images were recorded at the identical positions and the fluorescent particles were detected by means of their masses. A correlation analysis of data from fluorescence and SIMS results shows the suitability of the ToF-SIMS for the detection of nanoparticles in tissues. Furthermore, valuable additional information on the biological environment of nanomaterials can be obtained from the mass spectra and images.
Based on these results in a next step µ-XRF (quantitative imaging) was used to determine the distribution of nanoparticles on the lung before analysing the sample by ToF-SIMS. In this set-up ToF-SIMS enabled an improved lateral resolution and a lower detection limit compared to the µ-XRF results.