2.7.3. Transmission Electron Microscopy (TEM)

TEM (Holland Technai 20, Phillips, Amsterdam, The Netherlands) with bright field imaging and magnification technique was employed to examine the physical characteristics of SLN, such as particle size, shape, and surface morphology. A drop of the SLN dispersion was allowed to fix to the surface of a carbon coated copper grid, and the excess of dispersion was then wiped off using the tip of a filter paper. A drop of negative staining solution, 1% (*w*/*v*) phosphotungstic acid, was applied to the affixed SLNs, and extra stain was removed with a tissue paper [33]. The films were formed on grids by air drying at room temperature, and images were captured at 80 kV by TEM.
