Jem 2100

Isolated platelets were fixed with 2.5% glutaraldehyde in 50 mM cacodylate buffer (pH 7.2). After embedding in epon 812, ultra-thin sections were generated and subsequently stained with 2% uranyl acetate and lead citrate. Sample visualization was performed with a JEOL JEM-2100 microscope. The platelet cytoskeleton of spread mouse platelets on human fibrinogen was visualized by platinum replica electron microscopy (PREM). The cells were washed for 5 min in PHEM with 0.75% Triton X-100, 1 µM phallacidin, 1 µM paclitaxel, and 0.1% glutaraldehyde. Subsequently, samples were washed in PHEM, with 0.1 µM phallacidin and 0.1 µM paclitaxel. The cells were fixed in PHEM with 0.1 µM phallacidin, 0.1 µM paclitaxel, and 1% glutaraldehyde for 15 min, and were finally washed twice with filtered dH₂0. Subsequently, cells were treated with 0.1% tannic acid and 0.2% uranyl acetate, and dehydration was conducted in acetone. Critical point drying was performed in a Leica EM CPD300. Samples were coated with 1.2 nm of platinum with rotation at 45 °C and 3 nm of carbon at 90 °C without rotation under a high vacuum in a Leica EM ACE600. Finally, replicas were floated, picked up on formvar-carbon-coated grids and analyzed using a JEOL JEM-2100.

The morphology and structure of the PBAT composites were studied with scanning electron microscopy (SEM) (Hitachi, S-4800). The 10 nm gold–palladium was sputtered onto dried film samples using a Leica EM ACE200 sputter coater after being attached to a metal stub using double-sided carbon tape. Images were captured at an accelerating voltage of 20 kV. Transmission electron microscope (TEM) images were recorded with a JEM-2100 (JEOL, JEM-2100, Japan) at an acceleration voltage of 300 kV. Direct casting from the solution of the imaging samples onto copper grids followed by room-temperature drying has been used.

Ultra-thin sections were examined in transmission electron microscopes JEM1011 and JEM-2100 (Jeol, Japan) with accelerating voltages of 80 kV and 200kV, respectively, and magnification of x13000-21000. Images were recorded with Ultrascan 1000XP and ES500W CCD cameras (Gatan, USA). Tomograms were obtained from semi-thick (300–400 nm) sections using the Jeol Tomography software (Jeol, Japan). The tilting angle of the goniometer ranges from -60° to +60° (with a permanent step of 1 degree). A series of images were aligned by the Gatan Digital Micrograph (Gatan, USA) and then recovered with the back-projection algorithm in IMOD4.9. 3D sub-tomograms were visualized in the UCSF Chimera package [36 (link)].
Analytical electron microscopy was carried out on an analytical transmission electron microscope JEM-2100 (Jeol, Japan), equipped with a bright field detector for scanning transmission electron microscopy (SPEM) (Jeol, Japan), a High Angular Angle Dark Field detector (HAADF) (Gatan, USA), an X-Max 80 mm² Silicon Drift Detector (Oxford Instruments, UK), and a GIF Quantum ER energy filter (Gatan, USA). Scanning transmission EM (STEM) and TEM modes were used. The STEM probe size was 15 nm. Energy-dispersive X-ray (EDX) spectra collection and element analyses were performed in the INCA program (Oxford Instruments, UK).

A JASCO V-570 UV-Vis-NIR spectrometer was used to record the UV-Vis-NIR spectra in the 250 to 1200 nm wavelength range at 1 nm resolution. A JEOL JEM-2100 transmission electron microscope (HRTEM, 200 keV, JEOL, JEM-2100) and a scanning electron microscope (SEM, JEOL, JSM-7000F, FESEM) were used. High-resolution X-ray photoelectron spectroscopy (HRXPS) measurements were measured with a PHI Quantera SXM, ULVac-PHI Inc. A QM40 fluorescence spectrophotometer (PTI Ltd., Edmonton, AB, Canada) was used to record the fluorescence spectra. A Thermo Fisher Scientific K-Alpha 1063 X-ray photoelectron spectrometer (XPS, Thermo Fisher Scientific, Horsham, UK) was used for chemical analysis. A Perkin-Elmer system 2000 Fourier Transform Infrared spectrophotometer (FTIR) (Bomem model, DA-83FT) was used to record the FTIR spectra at 2 cm⁻¹ resolution. An atomic force microscope (Agilent, 5100 PicoLE) was used to record the AFM images and measure the size and thickness of GOQDs.

The morphologies of the synthesized materials were observed by field emitted scanning electron microscopy (FESEM, JSM-7800 F, JEOL, Tokyo, Japan) and transmission electron microscopy (TEM, JEM-2100, JEOL, Japan). HAADF-STEM characterization was conducted with TEM (JEM-2100, JEOL, Japan). The surface properties of the materials were characterized by X-ray photoelectron spectroscopy (XPS, ESCALAB 250Xi, Thermo Scientific, Waltham, MA, USA). The crystal structure was characterized by X-ray diffraction (XRD, MAXima-X XRD-7000, Shimadzu, Tokyo, Japan). The chemical groups of the samples were recorded by Fourier transform infrared spectroscopy (FTIR, Thermo-Nicolet 6700, Thermo Scientific, MA, USA) with air as a reference. Thermogravimetric analysis (TGA, TA Instruments Q50, TA Instruments, New Castle, DE, USA) was performed using a thermal analyzer under airflow (10 °C min⁻¹). JW-BK300C (JWGB SCI. & TECH., Beijing, China) determined N₂ adsorption-desorption isotherms and pore-size distributions. All electrochemical measurements were performed at room temperature on a CHI 760D (Chenhua Instruments, Shanghai, China). PBS (0.01 M, pH = 7.4) was used as the electrolyte for all electrochemical measures except in detection with cell viability.