Jem 2010 transmission electron microscope

NMR spectra were performed on a Bruker ARX 400 NMR spectrometer. Electrospray ionization mass spectrometry (ESI-MS) was performed on a Proteome X-LTQ. Particle size and size distribution were determined by laser light scattering (LLS) with a particle size analyzer (90 Plus, Brookhaven Instruments Co., United States) at a fixed angle of 90° at room temperature. The zeta potential was determined by a Malvern Zetasizer Nano ZS90 (Worcestershire, UK). TEM images were obtained from a JEOL JEM-2010 transmission electron microscope with an accelerating voltage of 200 KV. UV-vis absorption spectra were taken on a Shimadzu Model UV-1700 spectrometer. Photoluminescence (PL) spectra were measured on a Perkin-Elmer LS 55 spectrofluorometer. All UV and PL spectra were collected at 24 ± 1 °C.

All chemicals and reagents used in this work were AR grade 1 unless noticed and purchased from Sigma-Aldrich Chemical Corporation, including HAuCl₄, L-cysteine (L-Cys) and anhydrous FeCl₃. Other inorganic chemicals were purchased from Tianjin Chemical Corporation. Solvent water was purified and obtained from Millipore. All glassware was first treated with aqua regia at 40°C and then washed with purified water. XPS and DLS experiments were carried out by a PHI-5000 Versaprobe III X-ray photon–electron spectrophotometer (ULVCA-PHI, United States) and a Malvern Zetasizer Nano ZS90 laser particle size and zeta potential analyzer (Trek, Taiwan). IR spectra were recorded using a Bruker Vertex 70 FTIR spectrometer. The TEM image was obtained with a JEM-2010 transmission electron microscope (JEOL, Japan). UV-vis absorption spectra were obtained using a Shimadzu UV-3101PC spectrophotometer and a Biotek ELx800 automatic enzyme-linked immunosorbent assay. Emission spectra were recorded using a Hitachi F-7000 fluorescence spectrophotometer (Xe lamp). Emission quantum yield was determined by using this Hitachi F-7000 fluorescence spectrophotometer with the help of an integrating sphere. The reference was quinine sulfate (20 μM) in diluted H₂SO₄ (0.1 M). The emission lifetime was measured with a TEKTRONIX TDS-3052 oscilloscope (excited by an optical parametric oscillator).

JEM-2010 transmission electron microscope (, 80 kV, JEOL, Tokyo, Japan) was employed to examine 0.2 mg/mL MEVs. The samples were fixed in mesh carbon-layered copper grids (400) for 2 min and the surplus preparations were drained using blotting paper. Samples were then stained with 10 µL of 2% (w/v) uranyl acetate solution (Electron Microscopy Services) before imaging.

The phase composition of g-C₃N₄ was identified by XRD, recorded on a Rigaku D/max-3B X-ray diffractometer (Cu-K_α radiation, λ = 0.15418 nm) over the 2θ range of 10°-60° at 40 kV and 30mA. The chemical groups in g-C₃N₄ structure were confirmed by FT-IR, operated on a Nicolet Nexus infrared spectrometer after mixture of g-C₃N₄ sample with spectroscopic grade KBr (300 mg). The crystal morphology and microstructure of g-C₃N₄ were observed by SEM and TEM, realized on FEISirion200 scanning electron microscope and JEOL JEM-2010 transmission electron microscope, respectively. X-ray photoelectron spectroscopy (XPS) with Al Kα X-rays radiation (AXIS ULTRADLD, Kratos) was used to investigate the element compositions and surface properties of the samples. The binding energy was corrected using C1s (284.6 eV) as the internal standard. DRS spectra, recorded in the range of 400–800 nm, were implemented on an USB4000 UV-vis spectrometer (Ocean Optics) equipped with an integral sphere, using a standard template provided by South Africa Optics as the reference. The BET specific surface area of g-C₃N₄ was measured on a Sibata SA-1100 surface area analyzer, according to the nitrogen adsorption-desorption data at liquid nitrogen temperature. Surface Zeta potentials of g-C₃N₄ were examined by Zeta potential analyzer (Nano-ZS90) at different pH values.

EV samples (0.2 µg/µL) obtained from all four milk samples were examined in a JEM-2010 transmission electron microscope (JEOL, 80 kV, Akishima, Tokyo) or Tecnai TF30 transmission electron microscope (FEI, 300 kV, Lausanne, Switzerland), as described previously [35 (link)].