Field emission sem

Transmission electron microscopy (TEM) was carried out on a JEM-2100 electron microscope, operating at an acceleration voltage of 100 kV. Scanning transmission electron microscopy (STEM) was carried out on a JEM-2100F field-emission electron microscope, operating at an acceleration voltage of 200 kV. SEM images are captured with a JEOL Field Emission SEM. The concentration of the precursor PQDs solution was calibrated with reference to the mass of lead measured by an inductive coupled plasma optical emission spectrometer (Agilent 710). X-ray diffraction (XRD) patterns were acquired with a Bruker AXS D2 phaser X-ray diffractometer equipped with a Cu Kα radiation source (λ = 1.54 Å) at 40 kV and 30 mA. Infrared absorption spectroscopy was carried out on a BRUKER Vertex Fourier Transform Infrared spectrometer. UPS and XPS measurements were carried out on a VG ESCALAB 220i-XL surface analysis system equipped with a He discharge lamp (hν = 21.2 eV) and a monochromatic Al–Kα X-ray gun (hν = 1486.6 eV).

4×10⁵ colony-forming units (CFU) of BCG suspension in 7H9 medium was added into a 2 mL tube with or without ZnO-Se NPs in 7H9 medium. Then, the suspension of BCG were dropped onto small glass slides for 2h following the overnight fixation of BCG or H37Rv by 2.5% glutaraldehyde and 2% paraformaldehyde for 24 h. After that, the fixed BCG were washed by PBS and pure water, and further treated with 50%, 70%, 85%, 95%, 100% ethanol and HMDS (Hexamethyldisilazane), respectively. Then, the samples were gold sputter-coated and observed by a Field Emission SEM (JEOL, Japan).