Alpha 300r raman system

All-optical data were measured on the WITec Alpha 300R system, which has 50× objective lenses and a light spot of nearly 1 μm. Before the optical measurement, the pressure in the cryogenic chamber should be kept below 10⁻⁵ Pa, and then the chamber was heated to 350 K for 20 min to remove the water vapor. Finally, optical measurements were performed on the WITec Alpha 300R Raman system when the sample temperature reached 8 K. The model number of the cryogenic refrigeration system is C04-005-044 from Cryo Industries of America. The excitation light source of the SHG signal was a 1064 nm pulsed laser, and the excitation wavelength of the excitation light source measured by other data was 532 nm (2.33 eV). The angle data shown in Fig. 1e is fitted by a sine function, y = y₀ + A*sin (B*α + φ), where y is the intensity of SHG, y₀, A, B are constants, α is the angle of rotation of the half-wave plate, and φ is a fitting parameter defining the relative orientation of TMD crystal lattices. The twist angle between the two monolayers can be deduced by fitting the resulting function.

RM was performed using a customized WiTec alpha 300R Raman system (WiTec GmbH, Ulm, Germany) equipped with a green laser (532 nm) and a charged-coupled device spectrograph with a grating of 600 g/mm. Raman images comprising the whole cell area were acquired. 30 × 30 µm scans of single macrophages were acquired using a 63× apochromat water dipping objective (Carl Zeiss AG, Jena, Germany), an integration time of 0.5 s, a pixel resolution of 1 × 1 µm, and a laser power of 50 mW. A total of 30 cells were measured for each M0 and M1 replicate.