Emx plus 10 12 spectrometer

To further quantitatively analyze the production of ^•OH, a conventional colorimetric method based on the oxidation of TMB was conducted. Typically, the Fe‐MnPS₃/PDA‐PEG (500 ppm), H₂O₂ (1 mm), and TMB (20 mm) were efficiently mixed, and the total volume was 1 mL. After the reaction in darkness, the photographs and UV–vis–NIR absorbance spectra of oxidized TMB were acquired, respectively. The ^•OH generation was further assessed via a common MB degradation method. Specifically, Fe‐MnPS₃/PDA‐PEG nanosheets (500 ppm) were mixed with the MB (10 ppm) and H₂O₂ (1 mm) solutions and kept in darkness. The ^•OH‐induced MB degradation was determined by monitoring the decrease in the absorption peak of MB using a UV–vis–NIR spectrophotometer. Besides, electron paramagnetic resonance (EPR) was then applied to further verify the generation of·^•OH. 25 µL 5,5‐dimethyl‐1‐pyrroline N‐oxide (DMPO) solution (200 mm) was mixed with 25 µL solutions including H₂O₂ (1 mm) and Fe‐MnPS₃/PDA‐PEG nanosheets (500 ppm) under varying conditions. Subsequently, the mixture was instantly added to a capillary tube, and the EPR spectrum was acquired by a Bruker EMXplus‐10/12 spectrometer.

X-band (∼9.6 GHz) EPR spectra were recorded using EMX plus 10/12 spectrometer (Bruker), equipped with Oxford ESR-910 liquid helium cryostat. Briefly, 1 mM oxidized NCOA4 (as-isolated NCOA4) in Tris buffer (50 mM Tris, pH 8) and 10% (v/v) glycerol were transferred into a 4 mm diameter quartz EPR tube (Wilmad 707-SQ-250 M) and frozen in liquid nitrogen. EPR signals of oxidized NCOA4 were recorded at various temperatures (10 K, 25 K, and 45 K). Parameters for recording the EPR spectra were typically 2 G modulation amplitude, 9.40 GHz microwave frequency, and 2 mW incident microwave power; sweep time was 64 s.

¹H NMR spectra were measured by Bruker 600 MHz nuclear magnetic resonance spectrometer. Mass spectra were obtained by Thermo Q Exactive field orbital well cyclotron resonance mass spectrometer. IR spectra (solid infrared, liquid infrared and time-resolved infrared) were carried out by Thermo Nicolet iS50 FT-IR infrared spectrometer. UV-vis spectra were measured by a Thermo Evolution-220 spectrometer. Elemental analysis was measured by a vario EL CUBE. XRD was conducted by a Bruker Smart Apex II diffractometer. EPR was measured by a Bruker EMXPLUS10/12 spectrometer. Fluorescence spectra were measured by a FluoroMax-4 spectrofluorometer. The molecular weight of protein was analyzed by Bruker Ultraflex MALDI-TOF-MS spectrometer. Agarose gel electrophoresis was performed by DYY-6C electrophoresis apparatus of Beijing Liuyi Biological Technology Co., Ltd (Beijing, China). A cytotoxicity test was measured by SpectraMax iD5 microplate reader. Confocal microscopy images were analyzed by a LSM-880 confocal laser scanning microscope.