Confocal raman microscope alpha300r

WITecalpha300R confocal Raman microscope (Witec, Ulm, Germany) was used to analyze PEP-1-1. In short, 1 mg/mL of PEP-1-1 solutions was prepared, and 2 μL of it was dropped onto silver plates with a power of 20 mw and a scanning time of 20 s for analysis.

Raman spectroscopy data of pure (controls) and hybrid hydrogels were obtained with a WITec Confocal Raman microscope Alpha 300R+ (Ulm, Germany). Dried hydrogel samples were homogenized with PBS to avoid potential background fluorescence. Surface and in-depth distribution of the two different polymers inside hybrid hydrogels were determined using a frequency-doubled laser at 532 nm at an output power of 7 mW and 600 mm grating. Raman spectra for image compositions were recorded using a 100X Zeiss, EC Epiplan-Neofluar DIC objective (Oberkochen, Germany) with a numeric aperture of 0.9. Image resolution was set at 1024 × 127 active pixels, with a total of 22,500 spectra per image at a scan speed of 20 s per line and an integration time per pixel of 0.13 s. Data acquisition was driven by the WITec Control software (Ulm, Germany). Peak identification in hybrid hydrogels was recorded and compared.

The Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) samples were prepared by drop casting and drying the diluted ethanol GO suspension onto silicon oxide wafers. Raman spectra were carried out on a WITec Confocal Raman Microscope Alpha300R with a 532 nm laser. The XPS data were recorded with Kratos Axis Ultra DLD with Mg/Al achromatic source. SEM observations were conducted with a thermal field emission scanning electron microscope (FE-SEM, model: inspect F50 equipped with an energy-dispersive X-ray spectrometry (EDS). AFM results were measured by Veeco Multimode NanoScope IIIa in contact mode. The X-ray diffraction (XRD) and elemental analysis (EA) samples were oven dried powders from the GO suspension. The XRD patterns were obtained by Bruker D2 Phaser diffractometer with a Cu-Kα X–ray (λ = 1.5418 Å) radiation. EA data were acquired using Vario EL III. The UV-visible (UV-vis) and dynamic light scattering (DLS) samples were the aqueous GO suspension solutions. The UV-vis spectra were obtained using a V-600 UV–visible spectrometer in 0.06 mg/mL. DLS were collected on N5 Submicron Particles Size Analyzer. The cyclic voltammograms (CVs) were carried out with a conventional three-electrode configuration and a CHI614D electrochemical analyzer.

WITec Confocal Raman Microscope Alpha 300 R (WITec Inc., Ulm, Germany) is used to collect Raman spectra. a frequency-doubled Nd:YAG laser (Newport, Evry, France) with 532 nm wavelength and 50 mW power provided sample excitation. A 60x NIKON water immersion objective (numerical aperture of NA = 1.0.) focused laser beam on PBS immerged cells. an electron-multiplying charge-coupled device (EMCCD) camera (DU 970 N-BV353, Andor, Hartford, USA) captured the scattered signals. Using the formula r_lateral = 1.22·λ_laser/2·NA gives the spatial resolution of the system 325 nm. For the axial resolution, r_axial = 1.4·λ_laser·n/NA² (where n is the index of refraction 1.33 for the water-based objective) gives 991 nm. WITec Image Plus software performed data acquisition and processing. Calcium fluoride (CaF₂) substrate was employed due to its characteristic Raman peak at 320 cm⁻¹ to avoid extra Raman signal interfering with cells signature. Each Raman scan contains more than twenty thousand single spectra. The recorded Raman spectra collected from each voxel (300 nm × 300 nm × 900 nm) contain the sample biochemical fingerprint under the laser spot of 1 µm.

The Raman spectra and Raman maps were taken using a Witec Confocal Raman Microscope Alpha 300R using a 532 nm laser wavelength. The 25 μm × 25 μm Raman maps were constructed from 250 × 250 point spectra. The Raman maps for each deposition temperature were taken of the same region, respectively. For all integrated intensity maps, the 2D band was designated 2670–2730 cm⁻¹, the G band was designated 1560–1600 cm⁻¹, and the D band was designated 1325–1375 cm⁻¹. The TS₁ and TS₂ peaks were designated 1860–1910 cm⁻¹ and 2000–2050 cm⁻¹, respectively. The peak intensity ratios, seen in Table S1, were calculated using the peak height after background subtraction. The bin size for all histograms is 0.2.
The SEM images were taken using a JEOL 7600F Analytical SEM at an acceleration voltage of 2 kV and a working distance of 3mm in order to excite secondary electrons from the graphene layers. The TEM images were taken using a double aberration corrected JEOL ARM 200F at an acceleration voltage of 80 kV to mitigate any possible beam damage. The EBSD data was taken at an acceleration voltage of 20 kV and incidence angle of 70°. The mapping of the crystalline orientation takes into account this 20° offset geometry from normal which is why the [111] index is just above the pattern shown in Fig. 4d.