Dpph free radical scavenging capacity assay kit

The element composition and chemical valence of the membrane were determined by an X-ray photoelectron spectroscope (XPS, Thermo ESCALAB 250XI, USA) with 1486.6 eV Al Kα excitation source, and the results were analyzed by the C 1s peak at 285 eV. The positions and intensities of the absorption peaks of PLA/DLC membrane were recorded using Fourier transform infrared (FTIR) Tracer-100 Spectrometer (Shimadzu) and confocal micro-Raman spectrometer (InVia, Renishaw, UK), respectively. The scanning electron microscopy (SEM) images were captured to evaluate the membrane morphology with VEGA 3 TESCAN (Czech). The average fiber diameter and porosity of PLA and PLA/DLC membranes were measured using ImageJ 1.53 (USA) SEM images. The hydrophilism of the membranes was evaluated with water contact angles on a contact angle analyzer (DSA25S, Data Physics Corporation).
The methods and principles of radical scavenging test in vitro were well described previously [25 (link), 29 (link)]. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH ·) scavenging property was assayed with a DPPH Free Radical Scavenging Capacity Assay Kit (Solarbio, China) following the manufacturer’s instructions. The ·O₂⁻ scavenging property was test with a Superoxide Anion Activity Content Assay Kit (Solarbio, China) following the manufacturer’s instructions.

The scavenging abilities of ·OH, ·O₂⁻, DPPH and H₂O₂ were detected by the Hydroxyl Free Radical Scavenging Capacity Assay Kit (Elabscience, USA), Inhibition and Production of Superoxide Anionic Colorimetric Assay Kit (Elabscience, USA), DPPH Free Radical Scavenging Capacity Assay Kit (Solarbio, China), and Hydrogen Peroxide Colorimetric Assay Kit (Elabscience, USA) respectively, according to the manufacturer's instructions. Briefly, samples were mixed with working solution and incubated at 37 °C. The absorbance was detected by a microplate reader (Infinite M200 Pro, Tecan, Switzerland) at set time intervals.