Sirion 200 microscope

Transmission electron microscopy (TEM) images were taken on a JEM 2100 F microscope (JEOL, Japan) operated at 200 kV. Scanning electron microscopy (SEM) imaging was carried out on a Sirion 200 microscope (FEI, USA) operated at 5 kV. Nitrogen sorption isotherms were obtained at 77 K with a Micromertics ASAP 3020 analyzer (Micromertics, USA). Before each measurement, the sample was degassed in vacuum at 200 °C for at least 5 h. The Brunauer-Emmett-Teller (BET) method was used to calculate the specific surface areas of the samples. The Barrett-Joyner-Halenda (BJH) model was utilized to analyze pore size distributions, based on which total pore volumes could be obtained. Powder X-ray diffraction (XRD) data were collected with a MiniFlex 600 diffractometer (Rigadu, Japan) using Cu Kα radiation (40 kV, 15 mA). The X-ray photoelectron spectra (XPS) were recorded on an ESCALab MKII X-ray photo-electron spectrometer using Mg Kα radiation as an exciting source. The Co and B contents were determined with an Optima 7300 DV ICP-AES (PerkinElmer, USA). The N and C contents were analyzed with a VarioELIII element analyzer (Elementar Analysensysteme GmbH, Germany).

Scanning electron microscopy (SEM) images were obtained on a Sirion200 microscope (FEI Company, Eindhoven, the Netherlands) at an accelerating voltage of 10.0 kV. The infrared spectra were obtained from a Nicolet 6700 Fourier transform infrared (FT-IR) spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). X-ray diffraction (XRD) pattern was collected on a Bruker axs D8 advanced diffractometer (Bruker Corporation, Frankfurt, Germany) using Cu Kα radiation. X-ray photoelectron spectroscopy (XPS) spectra were collected on a Shimadzu Axis-Ultra multifunctional X-ray photoelectron spectrometer (Shimadzu Corporation, Tokyo, Japan) using an Al K X-ray source. Metal concentrations were confirmed using a Perkin-Elmer Optima 2100 (Perkin-Elmer Company, Waltham, MA, USA) inductively coupled plasma-optical emission spectrometry (ICP-OES).

S. aureus in TSB broth was added into wells of a 6-well tissue culture plate. LBA was then added to the final concentrations which were 1 × MIC and 0.5 × MIC. Sterile glass slides (10mm × 10 mm) were added to each well and incubated at 37 °C for 24 h. Each cover glass covered by biofilm was washed twice with PBS to remove non-adherent bacteria, and examined by field emission-SEM (FE-SEM) using a Sirion 200 microscope (FEI, Hillsboro, OR, USA) as previously described with minor modifications [19 (link)]. The biofilms were fixed in 1 mL of 2.5% glutaraldehyde for 12 h at 4 °C. The fixed cells were dehydrated in a gradient of 30, 50, 70, 90, 95, and 100% ethanol (v/v). After freeze-drying and gold coating, the S. aureus biofilm samples were observed by high-resolution FE-SEM using a Sirion 200 microscope at an accelerating voltage of 20 kV and 20,000× magnification. The group without LBA as the control.