Tecnai g2 f30 system

The X-ray diffraction (XRD, X’Pert PRO diffractometer, Cu Ka, Panalytical Company, Almelo, The Netherlands) was employed to characterize the crystal structure. A Fourier transform infrared (FT-IR) was analyzed on an Avatar 360 Nicolet instrument (Thermo Fisher Scientific, Shanghai, China). Scanning electron microscopic images and transmission electron microscopic images were measured using a Nova Nano SEM 450 system and the Tecnai G2 F30 system, respectively (FEI Company, Eindhoven, The Netherlands). A micromeritics ASAP 2020 analyzer (Norcross, GA, USA) was used to test Nitrogen adsorption–desorption isotherms.
A CHI 660E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd., Shanghai, China) was used for electrochemical measurements. The Cu-TCPP modified glassy carbon electrode (GCE, diameter: 3 mm), saturated calomel electrode (SCE), and platinum wire were used as the working electrode, reference electrode, and counter electrode, respectively.

Cryo-electron microscopy (Cryo-EM) was used to record the GSC-EVs size (40–150 nm) and morphology, as previously described [59 (link),62 (link)]. Briefly, 3 μL of freshly prepared GSC-EVs was applied to a glow-discharged carbon grid, vitrified and mounted into a Gatan cryo-holder (Gatan, Inc., Pleasanton, CA, USA) and stored in cold liquid nitrogen for analysis. Images of GSC-EVs were acquired using a 300 kV Tecnai G2 F30 system (FEI, Eindhoven, The Netherlands). A minimum of 15 fields of view were recorded per sample. The whole process was repeated at least 3 times.
Nanoparticle tracking analysis (NTA, NanoSight NS300 instrument, Malvern, UK) was used to record the size and particle concentration of GSC-EVs, using a previously described protocol [28 (link),29 (link)]. A sample mixture (100 µL of GSC-EVs: 900 µL of distilled water) was injected into the sample chamber using a 1 mL sterile syringe (BD, Franklin Lakes, NJ, USA), until the first droplet of liquid formed at the tip of the nozzle. Using the NTA software, the optimal field of view (50–100 particle/view) was set and recorded in triplicate for each sample. Data, including graphs of particle size and concentration/mL, were recorded and exported in csv or pdf format.