Lambda 365 spectrophotometer

The DPPH assay was carried out for the evaluation of the radical scavenging activity of MF and FeMF extracts. An aliquot of extract (50 μL) was added to a methanolic solution of DPPH 60 μM (1950 μL) and mixed for 30 min in the dark at 30 °C. The absorbance was recorded at 517 nm by a Perkin-Elmer Lambda 365 spectrophotometer and the extract concentration corresponding to 50% DPPH inhibition (EC₅₀) was determined according to Guimaraes et al. [28 (link)].

Scanning electron microscopy images were taken using a JSM-7100F scanning electron microscope (JEOL LTD, Akishima, Tokyo, Japan). X-ray diffraction pattens were obtained using a Rigaku minifle × 600 diffractometer (Rigaku, Tokyo, Japan). UV-Vis absorption measurements on powders’ suspensions in DMF were performed using a Perkin Elmer Lambda 365 spectrophotometer (PerkinElmer Inc., Waltham, MA, USA).
After washing both pristine (i.e., unmilled) mixture and ball milled powders thoroughly with hot water, Raman spectra was collected using a Thermo Scientific DXR Raman microscope (Thermo Fisher Scientific, Madison, WI, USA). The average in-plane size $L_a$ was estimated from Raman spectra using the equation [17 (link)]: $$L_a=\left(2.4\times {10}^{-10}\right){\lambda }_{laser}^4{\left(\frac{I_D}{I_G}\right)}^{-1}$$
where $I_D$ and $I_G$ are, respectively, the integrated intensities of D and G peaks in the Raman spectra.
X-ray photoelectron spectroscopy (XPS) spectra were collected using PHI 5000 VersaProbe (ULVAC Physical Electronics, Chanhassen, MN, USA). Transmission Electron Microscopy images were obtained using JEOL JEM-1011 Transmission Electron Microscope (JEOL LTD, Akishima, Tokyo, Japan).

UV–Vis spectra for tyraminium violurate solutions were recorded using a Hitachi U-3900H spectrophotometer in 1 cm cells at 25°C after equilibrating for 20 min. UV–Vis measurements for ground tyraminium violurates crystals mixed with barium sulfate were performed using the 50 mm transmission/reflectance sphere on PerkinElmer LAMBDA 365 Spectrophotometer at room temperature.

All chemicals were purchased from J&K Chemistry, Sigma-Aldrich and TCI, and used directly without further purification. Cells were obtained from the American Type Culture Collection.
¹H NMR and ¹³C NMR spectra were recorded with a Bruker ARX 400 NMR spectrometer. High-resolution mass spectra (HRMS) were recorded on a GCT premier CAB048 mass spectrometer operating in a MALDI-TOF mode. UV-Vis absorption spectra were recorded on a PerkinElmer Lambda 365 Spectrophotometer. Photoluminescence (PL) spectra were recorded on a Fluorolog®-3 Spectrofluorometer. The absolute fluorescence quantum yield was measured using a Hamamatsu quantum yield spectrometer C11347 Quantaurus QY. The lifetime was measured on an Edinburgh FLS980 fluorescence spectrophotometer equipped with a xenon arc lamp (Xe900). Single crystal X-ray diffraction was performed on a D/max-2550 PC X-ray diffractometer (XRD; Rigaku, Cu-Kα radiation). The crystal data were collected on an Oxford Diffraction Xcalibur Atlas Gemini ultra instrument. The scanning electron microscope image was taken using a JSM-6390 scanning electron microscope. The fluorescence images were taken by confocal laser scanning microscope (CLSM) (Zeiss, Germany).

The synthetic dyes MG, BBR, RB19, RB5, Ama, and RO16 were used to evaluate the decolorization capability of YRW2 Mb. The reaction mixture contained 5–60 μM dye and 5 μM YRW2 Mb, to which 5 mM H₂O₂ was added (final volume, 2 mL), in 50 mM potassium phosphate buffer, pH 7.0. After incubation for 0.5–1 h at room temperature on a rotary wheel, the absorbance spectra were recorded from 250 to 750 nm on a Lambda 365 spectrophotometer (PerkinElmer, Inc., Waltham, MA, USA). The control experiments were performed under the same conditions without the addition of the enzyme. The dye decolorization was expressed in percentage as follows [18 (link),50 (link)]:
Dec-l = [(Abst0 − Abst1)]/Abst0 × 100, where Dec-l is the decolorization level (%), and Abst0 and Abst1 are the absorbance values before and after treatment, recorded at 617, 555, 595, 595, 520, and 490 nm for MG, BBR, RB19, RB5, Ama, and RO16 dyes, respectively.