Ph meter model 744

The in vitro digestion of LHEPS and LPEPS was performed by our previous methodologies with minor modifications [27 (link)]. The procedure was initiated with a simulated human salivary phase, followed by a gastric phase and an intestinal phase. A pH-meter model 744 (Metrohm AG, Herisau, Switzerland) was applied for monitoring the pH of the digestion solution. For the buccal phase, 10 mg of LHEPS or LPEPS was added to the 4 mL mixture of salivary α-amylase and amyloglucosidase, and 10 mL buffer solution. The digestion solution was carried out in a shaking water bath (MaxQ™ 7000, Thermo Fisher, Waltham, MA, USA) for 10 min (37 °C, 55 rpm). For the gastric phase, the pH of digestion solution was adjusted to 2.0 using 1 M HCl, then pepsin was added to a final concentration of 3.0 mg/mL and incubated at 37 °C for 2 h in darkness while stirring (55 rpm). For the intestinal phase, 4 mL mixture of pancreatin, trypsin, pancreatic α-amylase, and bile salt solution was added and 1 M NaOH was applied to regulate the pH of the digestion solution. The digestion phase was continued at 37 °C, 150 rpm for 8 h. Finally, the mediums were inactivated immediately at 100 °C for 5 min and filtered before analysis. Each in vitro simulated saliva and GSI digestion was conducted three times or more to ensure repeatability.

Electrochemical measurements were performed with a SAMA-500 electroanalyzer (SAMA Research Center, Iran) and an Autolab electrochemical analyzer (Metrohm Autolab B. V., Utrecht, The Netherlands). All electrochemical experiments were carried out in a conventional three-electrode cell at room temperature. A platinum electrode and a silver/silver chloride electrode (Ag/AgCl) were used as the counter and reference electrodes, respectively. A modified CCE with BB was used as working electrode. A Metrohm pH meter, model 744 was used for pH measurements. TEM images were taken using a Philips CM120 transmission electron microscopy with 2.50 Å resolution.

This study was conducted using a “digital pH meter HANNA, model 211 (HANNA instruments, Rhode Island, Woonsocket, RI, United States) and the pH meter Metrohm pH-meter model 744 (Metrohm Co., Herisau, Switzerland) was used to adjust the pH of the sample solution throughout the experiments. The designed potentiometric system was consisted of a constructed conventional naltrexone hydrochloride-tetraphenyl borate (NTX-TPB) or modified NTX-TPB-CuO/Al₂O₃ nanocomposite coated wire sensor in conjunction with silver/silver chloride (Ag/AgCl) as reference one. The synthesized metal oxide nanoparticles and the nanocomposite were characterized using various spectroscopic and microscopic techniques, including UV-2450 spectrophotometer (Shimadzu Corporation, Kyoto, Japan), Fourier-Transform Infrared spectroscopy (FT-IR) Spectrum BX spectrometer (PerkinElmer, Waltham, Massachusetts, United States). X-ray diffraction (XRD) Shimadzu XRD-6000 diffractometer (Shimadzu, Kyoto, Japan), scanning electron microscope (SEM) JSM-7610F (JEOL Ltd., Tokyo, Japan), and a transmission electron microscope (TEM) JEM-2100F, (JEOL Ltd., Tokyo, Japan). Furthermore, Energy-Dispersive X-Ray Spectroscopy (EDX), using EDX-8100 (Shimadzu, Kyoto, Japan) analysis was applied to detect the presence of Cu, Al and O elements in the synthesized nanomaterials.