Inspect f feg sem

Transmission electron microscopy (TEM) was carried out on a FEI TECNAI 20 transmission electron microscope at 200 kV. The absorbance and fluorescence spectra were obtained on a BioTek Synergy MX multi-mode microplate reader. Scanning transmission electron microscopy (STEM) image was obtained using FEI G2 TECNAI F30 at 300 kV. The zeta potential and size distribution measurements were carried out on a Malvern Zetasizer Nano ZS system (Zeta potential +33.3mV, DLS 2.01nm). Energy-dispersive X-ray spectroscopy (EDS) and element mapping were performed on a FEI Inspect F FEG-SEM equipped with EDZX EDS system to confirm Gd contents in the carbon dots. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Gd concentration in the sample for further study.

Scanning electron microscopy (SEM) is a useful tool to understand the surface characteristics of a polymer. In the present study, microstructure and surface morphology of the wound dressing (before and after NO donor incorporation) were examined using SEM (FEI Inspect F FEG-SEM).³⁵ A total of three samples of each of the control (without GSNO) and alginate–PVA–GSNO were sputter coated with gold–palladium (10 nm) using a Sputter Coater (Leica EM ACE200) after mounting them on a metal stub. An accelerating voltage of 5 kV was used to capture SEM images of the sample at 100× magnification.

The surface morphology and roughness of the polymer composites were examined by SEM (FEI Inspect F FEG-SEM). Dried composite samples were mounted on a metal stub with double-sided carbon tape and sputter-coated with 10 nm gold–palladium using a Leica EM ACE200 sputter coater. An accelerating voltage 5 kV was used for the experiment.
Microscopic images of S. aureus on the polymer composites were obtained after exposing the composites to S. aureus for 24 h. Bacteria were collected in the mid-exponential growth phase and were diluted with PBS buffer to attain 10⁸ CFU mL⁻¹. Subsequently, the polymer composites were incubated at 37 °C in 2 mL bacteria solution in a 24-well plate under shaking condition (150 rpm). After 24 h, the polymer composites were washed with PBS buffer to get rid of any planktonic or loosely attached bacteria. The composites were fixed with 3 % glutaraldehyde in 0.1 M PBS solution for 16 h. The samples were dehydrated with graded ethanol for 20 min (50, 60, 70, 80,90, and 100 vol. %). Finally, the samples were soaked and washed in HMDS and left to air-dry overnight in the fume hood away from light. Each sample was mounted and sputter-coated with gold-palladium, and random spots were chosen for imaging. The experiment was repeated three times using different passages of bacteria. Representative images have been shown.