Jem 2100f field emission high resolution transmission electron microscope

The plant samples were fixed first in fixation buffer I (5% glutaraldehyde and 0.1 M phosphate, pH 7.4) for 4 h at room temperature and then in fixation buffer II (2% osmium tetroxide and 0.1 M phosphate, pH 7.4) at 4 °C overnight. After one wash in phosphate buffer and two washes in double-distilled water, the samples were stained for 1 h in 1% (m/v) uranyl acetate. After another wash in double-distilled water, the samples were dehydrated through a gradient of alcohol (from 30%, 50%, 70%, to 85%) and then embedded in Spurr’s resin (Sigma-Aldrich). Ultrathin sections of 70 nm were prepared using the UC7 μLtramicrotome (Leica Microsystem) and mounted on the AG100M molybdenum grids with a single slot (Agar Scientific) to minimize the background for copper. The sections were stained with uranyl acetate and lead citrate, observed, and photographed using a Tecnai G2 20 Twin electron microscope (FEI) at 120 kV. EF-TEM for copper element analysis was carried out on the same specimen using a JEM-2100F field-emission high-resolution transmission electron microscope equipped with the energy filter (JEOL). Three individual leaves were used for each genotype and at least 10 cells were analyzed per sample.

The particle size and zeta potential of agSWCNHs and SWCNHox suspensions were determined by dynamic light scattering using a Malvern Zetasizer Nano ZS (Malvern, UK) at 25°C. C, H, and N elemental analysis of agSWCNHs and SWCNHox was carried out on a Vario ELIII Element Analyzer (Elementar Analysensysteme GmbH, Hanau, Germany). Infrared (IR) spectra of agSWCNHs and SWCNHox were measured in the spectrum region of 4,000–400 cm⁻¹ by using a PerkinElmer Fourier transform infrared (FTIR) spectrophotometer (Thermo-Nicolet Nexus 470 FTIR spectrometer; Thermo Nicolet Corporation, Madison, WI, USA). Transmission electron microscope images and energy-dispersive spectrum (EDS) of SWCNHs and SWCNHox were obtained using a JEM2100F field-emission high-resolution transmission electron microscope (JEOL Ltd.). The fluorescence images of F-B-SWCNHox were examined using a confocal laser scanning microscope (Leica TCS SP8; Leica Microsystems, Wetzlar, Germany) at an excitation wavelength of 488 nm.