Uh5300

The functional groups of HA fractions were analyzed by Fourier transform infrared spectroscopy (FTIR, Nicolet iS 5, Thermo Fisher Scientific, Madison, USA) in the wave number range of 4000 to 400 cm⁻¹. The light absorption properties of HA fractions were characterized using UV-vis spectrophotometry (Hitachi UH5300, Ibaraki, Japan). Fluorescence spectra of the HA fractions were obtained using a Hitachi F-4500 fluorescence spectrophotometer (Japan). The emission spectrum between 380 and 650 nm with excitation at 360 nm was recorded, and excitation-emission matrix (EEM) spectra were obtained by continuous scanning of the emission (Em) wavelength from 220 to 600 nm by increasing the excitation (Ex) wavelength from 200 to 450 nm. TOC was measured using a TOC analyzer (LiquiTOCII, Elementar Analysensysteme GmbH, Langenselbold, Germany).

Shoot tissue was sampled in 1.5 ml tubes and fresh weight was determined. 80% (v/v) of cold acetone solution was added and left overnight at 4 °C in dark. Samples were then centrifuged at 4 °C, 15,000 rpm for 15 minutes, and absorbance of the supernatant solution was measured at 646 nm, 663 nm, and 750 nm with a double-beam spectrophotometer (HITACHI UH5300). The amount of chlorophyll in the aboveground tissue was determined from the concentration of chlorophyll in the solution, which was calculated from the following formula using the measured values.
$$Chla+b\left[\mu ,M\right]=19.54\times \left(A_{646},-,A_{750}\right)+8.29\times \left(A_{663},-,A_{750}\right)$$

Zeta potential was detected by Malvern Zetasizer Nano ZS (Zetasizer Nano ZS 90, Malvern Instrument, UK) at 25 °C. The morphological of hydrogel was recorded by scanning electron microscopy (SEM, ZEISS-SUPRA55, Germany). Rheology tests were performed on the rheometer (MCR 302, Aaton paar, Austria) to investigate mechanical properties and stability of NCTD Gel. In order to explore self-assembly mechanism of NCTD Gel, thermodynamic mechanism was recorded on a NANO ITC (TA, USA). UV–vis spectra were recorded on a UV–vis spectrophotometer (HITACHI UH5300, Japan) with the range of 200–400 nm. FT-IR spectra were recorded on a Fourier transform infrared spectrometer (NicoletiS10, Thermo, USA) with the range of 4000-400 cm⁻¹. CD spectra were obtained by using Chirascan V100 (Applied Photophysics, UK) with the range of 200–400 nm. ¹H-NMR (Avance IIIHD 400 MHz spectrometer, Bruker, America) spectra were used to ensure the formation mechanism between GA and NCTD. MD simulation was performed by GROMACS 2019.6 software to reveal the self-assembly mechanism of NCTD Gel.

The affecting factors of dose (5–30 g/L), contact time (3–18 h), temperature (20–50 °C), pH (3–11), and concentration (30–90 mg/L) with the control condition of initial DR28 dye concentration of 50 mg/L, a sample volume of 100 mL, and a shaking speed of 150 rpm by using an incubator shaker (New Brunswick, Innova 42, USA)^{8 (link),9 (link),20 (link)} on DR28 dye removal efficiencies of SBB, SBBT, SBBM, SBBA, and SBBZ were investigated through a series of batch experiments which referred from the previous study of Praipipat et al.^{18 (link)} Their optimum conditions were chosen from the lowest dose or contact time or temperature or pH or concentration with obtaining the highest DR28 dye removal efficiencies^{9 (link)}. UV–VIS Spectrophotometer (UH5300, Hitachi, Japan) with a wavelength of 497 nm was used for analyzing dye concentrations, and the triplicate experiments were investigated to verify the results and report the average value. Dye removal efficiency in the percentage and dye adsorption capacity is calculated following Eqs. (1)–(2): $$\text{Dye removal efficiency}\left(\%\right)=\left(\left(C_0-C_{\text{e}}\right)/C_0\right)\times 100$$ $$\text{Dye adsorption capacity}\left(q_e\right)=(C_0-C_{\text{e}})V/m$$ where C_e is the dye concentration at equilibrium (mg/L), C₀ is the initial dye concentration (mg/L), q_e is the capacity of dye adsorption on adsorbent material at equilibrium (mg/g), V is the sample volume (L), and m is the amount of adsorbent material (g).

The SPR of the green-synthesized AuNPs was evaluated using an UV–Vis spectroscopy (UH-5300, Hitachi, Japan) device in the scanning range 400–800 nm. The AuNPs were also analyzed using a dynamic light scattering (DLS; Zetasizer Nano S90, Malvern) apparatus to determine their size distribution profile and zeta potential values. The participation of biological molecules to the synthesis of AuNPs was analyzed using a Fourier-transform infrared (FTIR; FTS 7000, Varian, Australia) spectroscopy in the scanning range 500–4000 nm. The size and shape of the green-synthesized AuNPs were analyzed using a transmission electron microscopy (TEM; JEM-3010, JEOL, Japan) instrument. Furthermore, the elemental composition of the AuNPs was examined using energy-dispersive X-ray spectroscopy (EDX).

The biosynthesized PdNCs were characterized by ultraviolet-visible (UV/Vis) spectroscopy (UH-5300, Hitachi, Japan) in the scanning range of 300–800 nm. The size distribution profile of the PdNCs was analyzed via dynamic light scattering (DLS; Zetasizer Nano S90, Malvern). Fourier transform infrared (FTIR) spectroscopy (FTS 7000, Varian, Australia) was performed to elucidate the role of biological molecules in the synthesis of nanoclusters. The morphology, size, d-spacing (inter-atomic spacing), and crystalline nature of the PdNCs were characterized via transmission electron microscopy (TEM; JEM-3010, JEOL, Japan). Meanwhile, the elemental composition of the nanoclusters was identified via energy-dispersive X-ray spectroscopy (EDX). The X-ray diffraction patterns were determined with an X-ray Diffractometer (X’Pert PRO, PANanalytical, Netherland) with CuKα radiation (λ = 1.5417 Å). The freeze-dried nanoclusters were further analyzed using scanning electron microscopy (SEM; Zeiss, EVO 18, Germany). The oxidation state of the PdNCs was evaluated using X-ray photoelectron spectroscopy (XPS; Thermo Scientific, UK).