Tecnai g2 t20 x twin

Transmission electron microscopy (TEM) analysis was performed by means of a high-resolution transmission electron microscope Tecnai G2 T20 X-TWIN (FEI) equipped with an energy dispersive X-ray spectrometer (EDS). The samples were prepared for analysis by scratching the film from the surface of the electrode and placing it on a TEM copper grid. Moreover, microscopic images of the pSPCE/PbNPs surface were attained with a high-resolution scanning electron microscope Quanta 3D FEG (FEI, USA) (acceleration voltage of 5.0 kV, working distance of 9.3 mm, magnification of 25,000×).
All voltammetric studies were made using a µAutolab electrochemical analyzer (Eco Chemie, Utrecht, The Netherlands) controlled by GPES 4.9 software. The standard quartz electrochemical cell with a volume of 10 mL composed of a commercially available screen-printed carbon sensor (SPCE, DropSens, Spain, Ref. C150) was applied for experiments. The SPCE sensor consisted of a screen-printed carbon working electrode, a platinum screen-printed auxiliary electrode, and a silver screen-printed pseudo-reference electrode. The µAutolab analyzer controlled by FRA 4.9 software was used for electrochemical impedance spectroscopy (EIS) measurements.
HPLC analyses were performed on a VWR Hitachi Elite LaChrom HPLC with a PDA detector using an Ascentis Express C18 column (15 cm × 2.1 mm i.d., 2.7 μm).

Transmission electron microscopy (TEM) images were recorded using FEI Tecnai G2 T20 X-TWIN, Hilllsboro, OR, USA. The powder samples were added to acetone (chromatographic grade) and sonicated. Then, a drop of the suspension was deposited onto a copper grid with a thin carbon film. After acetone evaporation, sample particles that remained on the film were studied with TEM. Additionally, the surface morphology and grain size distribution was analyzed using atomic force microscopy (AFM, Nanoscope V Digital Instruments, Boston, MA, USA, with a Tapping Mode technique). AFM data processing was performed using the SPIP program (version 5.0.6, Hørsholm, Denmark).

The TEM analysis of PSE-treated mycobacteria was performed by negative staining [20 (link)]. After pretreatment with the NALC-NaOH solution, the Mycobacterium cells were fixed with 4% glutaraldehyde. After that, the bacterial cells were suspended in water mixed in a 1:1 ratio with a contrast solution (1% natrium silicotungstate, 0.5% ammonium molybdate) and micropipetted on TEM grids (3 mm mesh) coated with formvar film. The mixture was incubated for 10–15 min to pellet the cells on the mesh surface; afterwards, the solution was removed with filter paper. The grids were dried in a pre-vacuum during the specimen holder transfer into the microscope column. The observations were carried out using a Tecnai G2 T20 X-TWIN (FEI) transmission electron microscope.