Tecnai g2 20 x twin electron microscope

The transmission electron microscopy (TEM) measurements were performed to measure the morphology and size distribution of lipid nanocarriers. Images were taken using an FEI Tecnai G2 20 XTWIN electron microscope (FEI, Hillsboro, OR, USA). The size distribution of the nanocarriers for each sample was determined by counting the size of approximately 250 nanocarriers from several TEM images obtained from different parts of the TEM grids. A few drops of the diluted suspension were placed on the grid and stained with 2% uranyl acetate, and then the image was captured. The size distribution plots were fitted by using Gauss curve approximation.

The morphology of the obtained NCs was studied by atomic force microscopy (AFM) and transmission electron microscopy (TEM) according to our previous protocols [7 (link),21 (link)]. The AFM observations were conducted using a NanoScope Dimension V instrument with an RT ESP tube scanner (Veeco Instruments, Plainview, NY, USA) Samples were analyzed at 0.5 Hz scanning speed using a low-resonance-frequency pyramidal silicon cantilever resonating at 250–331 kHz at a constant force of 20–80 N/m. The resonance amplitude was adjusted manually to the lowest possible amplitude enabling stable imaging within the contamination layer on the surface. We prepared the samples by adsorption of an NC droplet on mica that was freshly cleaved. After 18 h, the excess substrate was removed by rinsing the mica plates in double distilled water for 1 min and drying for 2 h at room temperature. The TEM imaging of NCs was performed with an Field Electron and Ion Company (FEI) Tecnai G2 20 X-TWIN electron microscope (FEI, Brno, Czech Republic) by placing a few drops of diluted NCs on a Cu-Ni grid and leaving the specimens to dry for 20 h at room temperature.

The electrodeposition of silica thin films (chronoamperometry with controlled potential) as well as their analysis by differential pulse anodic stripping voltammetry (DPASV) was carried out using potentiostat/galvanostat SP150 (Biologic) at room temperature in the three-electrode configuration.
The working electrode was a conductive substrate (fluoride-doped tin oxide (FTO)-covered glass) in the case of electrodeposition of silica thin films (see next section) and the same substrate with deposited thin films containing the anchored silver ions for DPASV measurements. As the counter electrode, we used a platinum plate, while the reference electrode was standard Ag/AgCl. DPASV measurements were carried out in 0.1 M NaNO ${}_3$ electrolyte solution. For synthesis and electrochemical experiments, we used custom fabricated Teflon cell, allowing for the application of the substrate at the bottom.
The TEM imaging was carried out using the FEI Tecnai G2 20 X-TWIN electron microscope, equipped with emission source LaB6 and CCD camera FEI Eagle 2K. The TEM images were processed (Fourier frequency transformation) using the Gwyddion software [47 (link)].