Jem 2011 electron microscope

The morphology and structure of VLPs from crude supernatants was assessed with two different electron microscopy techniques, including negative staining transmission electron microscopy (NS-TEM), and cryogenic transmission electron microscopy (cryo-TEM) as described previously [22 (link)]. For NS-TEM, 8 µL of sample were deposited on carbon-coated cooper grids (Micro to Nano, Wateringweg, The Netherlands) previously subjected to a glow discharge treatment (PELCO, Fresno, CA, USA) and incubated at room temperature for 1 min. Excess sample was carefully drained off the grid with the aid of filter paper. Then, 8 µL of 2% w/v uranyl acetate were added, and samples were incubated for 1 min at room temperature. Excess stained was drained off and grids were dried at room temperature until analysis. Sample visualization was performed in a JEM-1400 transmission electron microscope (JEOL, Akishima, Tokyo, Japan) equipped with an ES1000W Erlangshen charge-coupled device camera (model no. 785, Gatan, Pleasanton, CA, USA).
For cryo-TEM, 2 µL of sample were blotted on 400 mesh glow discharged Holey carbon grids (Micro to Nano). Samples were then plunged into liquid ethane at −180 °C using a Leica EM GP cryogenic workstation (Leica Microsystems) and visualized in a JEM-2011 electron microscope (JEOL) operating at 200 kV and equipped with a CCD multiscan camera (model no. 895, Gatan).

Initial specimen characterisation was performed using PXRD on a PANalytical Empyrean diffractometer, using Cu K_α radiation. Particle size and morphology of the samples were examined using SEM images, which were recorded on a JEOL JSM-6700F field emission gun microscope with an accelerating voltage of 3 or 5 kV. The samples for SEM was coated with gold using a Quorum Technologies Q150RES sputter to reduce the charging effect. The local crystal structures were detected using HRTEM. The TEM and HRTEM images were recorded on a JEOL JEM-2011 electron microscope operating at 200 kV. The local Mn : Co ratios of the samples were detected by using EDX. For some specimens with a poor homogeneity, more than 10 particles were examined to get an average value of Mn/Co.

Transmission Electron Microscopy was used to observe the morphology and analyze the elemental composition of the AgNPs [13 (link)]. A drop of AgNP dispersion was placed onto a carbon-coated 300 mesh copper grid and the grid was air-dried. The prepared samples were observed on a transmission electron microscope (JEM-2011 Electron Microscope, JEOL USA, Inc., Peabody, MA, USA) at an accelerating voltage of 200 kV. Images were recorded with a Gatan MultiScan 794 Camera and processed with Gatan Digital Micrograph 3.1 software package (Gatan, Pleasanton, CA, USA) and the particle size of AgNPs was measured at the same time. In addition, an energy dispersive spectrometer attached to the TEM system was used to obtain the energy dispersive spectroscopy (EDS) of AgNP during TEM observation for element content analysis of AgNP dispersions.