Is50 spectrometer

Furfuryl-modified gelatin was synthesized through a coupling reaction between the amine groups of gelatin and furfuryl glycidyl ether. First, gelatin (2 g) was dissolved in 80 mL of deionized (DI) water and the pH was adjusted to 11 using 1 N NaOH. Next, furfuryl glycidyl ether (250 μL) was mixed with DMSO (20 mL). Then, these two solutions were mixed and incubated at 60 °C for 30 h with gentle stirring. The pH of the furfuryl-gelatin solution was adjusted to 7 and dialyzed for 48 h using a dialysis membrane (MWCO 1000 Da, Spectrum Laboratories, Inc., Rancho Dominguez, CA, USA). The dialyzed furfuryl-gelatin solution was lyophilized and then washed four times with acetone and once with ether. The solution was then dried at 37 °C for 6 h and stored for further use.
The synthesized furfuryl-gelatin was analyzed using ¹H-NMR (500 MHz) using JNM-ECZ500R/S1 (JEOL, Tokyo, Japan). Gelatin and furfuryl-gelatin were dissolved in D₂O (50 mg/mL) for the measurements.
Fourier-transform infrared (FT-IR) spectra were obtained at room temperature using an iS50 spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). The transmittance of the lyophilized samples was measured using KBr pellets within the range of 4000–500 cm^–1.

Diffuse reflectance spectra of Bi₂Te₃ powders were measured using an iS50 spectrometer (Thermo Fisher, USA). The absorption coefficient was calculated from the reflectance by the Kubelka–Munk equation: F(R) = (1−R)²/2R, where R is the optical reflectance.

The VPP polymer films were characterized by Fourier transform infrared (FTIR) spectroscopy using a Thermo Fisher Scientific (Waltham, MA, USA) iS50 spectrometer. Scanning electron microscopy (SEM) images were recorded using a FEI Quanta 600 FEG SEM. The response of the sensor was measured using a biologic Sp-150 potentiostat.

The atomic force microscopy (AFM) images were obtained using a Bruker Dimension Icon scanning probe microscope (SPM) in PeakForce tapping mode. The scanning electron microscopy (SEM) images were obtained from the Hitachi SU8220 device (Ibaraki, Japan). The water contact angle was measured using an automatic contact angle measuring instrument (Biolin, Attension Theta, Gothenburg, Sweden). The X-ray photoelectron spectroscopy (XPS) analysis was carried out using a theta probe spectrometer (Thermo Fisher, Brno, Czech Republic) with monochromatic Al-Kα radiation (1486.6 eV). Raman spectroscopy was performed on a Renishaw inVia Reflex Raman microscope (London, England) with 633 nm laser excitation. The FTIR characterization was carried out using a Thermofisher IS50 spectrometer (Brno, Czech Republic) in attenuated total reflection (ATR) mode in the wavenumber range of 400–4000 cm⁻¹. The X-ray diffraction (XRD) analysis was performed using Rigaku Smart Lab X-Ray Diffractometer (Japan) with filtered Cu-Kα radiation (40 kV and 40 mA, λ = 0.154 nm).

The hBNs were dispersed in double distilled water (ddH₂O) by sonication for 2 min at before the analysis (Bandelin Sonopuls HD 3100). A Perkin Elmer Lambda 25 UV-Vis spectrometer was used to obtain absorption spectra. IR spectra were acquired with a Thermo NICOLET IS50 Spectrometer. XRD analysis was performed using a Shimadzu XRD-6000 with a ICDD PDF 4 software. The scanning area was in continuous mode with a scanning range of 2.000–69.980° and a scanning speed of 2.0000°/min. The sampling pitch was set to 0.0200°, and the preset time was set to 0.60 s. Raman spectra of the hBNs were recorded using a Renishaw In Via Reflex Raman Microscopy system (Renishaw Plc., New Mills, Wotton-under-Edge, UK) equipped with a 514 nm Argon ion laser. A minimum of 16 spectra was acquired from a 16-μm² hBNs sample area. All measurements were performed at least three times.