Cm30 tem stem

Concerning their physicochemical features, MNPs were analyzing regarding their size, iron content according to previous studies (Friedrich et al. 2021 ; Mühlberger et al. 2019 (link); Stein et al. 2020 ). Their iron content in milligram per milliliter was investigated after diluting them 1:20 in deionized H₂O, liquefying them in 65% nitric acid with atomic emission spectroscopy (AES), using Agilent 4200 MP-AES with an iron solution of 1000 mg Fe/l as an external standard (Bernd Kraft, Duisburg, Germany). MNP particles were diluted to the desired concentration with deionized water for all experiments. Transmission electron microscopy (TEM) images were acquired using the CM30 TEM/STEM (Philips, The Netherlands) operating at 300 kV acquired with a CCD camera, a Tietz Fast Scan-F114 (Tietz Video and Image Processing Systems GmbH, Gauting, Germany). Dispersions at a concentration of 100 µg Fe/ml were dropped onto a carbon-coated copper grids (Plano, Germany) an air-dried at RT.

Transmission electron microscopy (TEM) images were taken using a CM30 TEM/STEM (Philips, The Netherlands) operating at 300 kV. Specimens were prepared by drop casting diluted nanoparticle dispersions onto carbon-coated copper grids (Plano, Germany). For the CCD camera, a Tietz Fast Scan-F114 (Tietz Video and Image Processing Systems GmbH, Gauting, Germany) was used.