Jem 1011 electron microscopy

Kidneys were collected, cut into small tissue blocks (1 mm³), and fixed in 2.5% glutaraldehyde at 4 °C. For transmission electron microscope, the fragments were washed in 0.1 M sodium cacodylate buffer, after, postfixaded with 2% osmium tetroxide, tissues were dehydrated in increasing series of acetone (30, 50, 70, 90 and 100%), 15 min each step, and embedded in epoxy resin for three days at 60 °C. Ultrathin sections were contrasted with uranyl acetate and lead citrate. Sections were examined with a JEM1011 electron microscopy (JEOL, Akishima, Tokyo, Japan).
For scanning electron microscopy, the fragments were washed in 0.1 M sodium cacodylate buffer, postfixed with 1% osmium tetroxide diluted in 0.1 M sodium cacodylate buffer. After further washing, the material was dehydrated in an increasing series of ethanol (30, 50, 70, 90% and 2× absolute), 30 min each step. The material was taken to the critical point device for the replacement of ethanol by CO₂, later fixed in stubs with carbon tape and metallized with gold. After metallization, the material was analyzed using a scanning electron microscope JEOL-JSM-6390-LV (JEOL, Akishima, Tokyo, Japan).

Transmission electron microscopy (TEM) samples were prepared by dropping the nanoparticles colloids (10 μL) onto copper grids and dried under infrared light. The photograph was available at an accelerating voltage of 80 kV on JEM-1011 electron microscopy (JEOL, Tokyo, Japan). The size distribution and zeta potential of the SeNPs were examined using the Malvern Zetasizer Nano ZS (Worcestershire, UK). The UV–vis absorption spectrum of the HE-SeNPs was acquired using a scanning spectrophotometer (Mapada, Shanghai Shi, China) with a 1 cm path length. Energy dispersive X-ray spectroscopy (EDS) was carried out to detect the elemental composition of HE-SeNPs. The analysed sample was firstly photographed by SEM and then the selected photograph was subjected to elemental analysis by EDS (Bruker Inc., Madison, WI).