Sorvall legend micro 21r

Component weighing was performed on a laboratory scale (Ohaus, Parsippany, NJ, USA). Sample centrifugation was performed on a Sorvall Legend Micro 21R microcentrifuge (Thermo Fisher Scientific, Waltham, MA, USA). Absorbance measurements were performed on a Varioskan LUX multimode plate reader (Thermo Fisher Scientific, Waltham, MA, USA). Absorbance data were analyzed using the Skanit-RE software v5.0 (Thermo Fisher Scientific, Waltham, MA, USA). Immunohistology sample preparation was performed using a Ventana Discovery ULTRA system (Roche Diagnostics, Rotkreuz, Switzerland). Immunohistochemistry imaging was performed on an inverted IX81 fluorescence microscope (Olympus, Tokyo, Japan). Macroscopic imaging was performed on an iPhone 12 (Apple, Cupertino, CA, USA).

Mixtures of DOPC/DOPE-pAA-Cys5 = 95 : 5 mol% or DOPC/DOPE-pAA-Cys5/Texas-Red-DHPE = 94 : 5 : 1 mol% were suspended in isopropanol. Lipid dry films were prepared following the gentle evaporation of isopropanol by a flow of N₂ gas in a glass vial and storage in a vacuum chamber at room temperature overnight. The films were resuspended at a final concentration of 1 mg mL⁻¹ in 100 mM NaCl buffered with 10 mM Tris–HCl (pH = 7.4). The products were then sonicated for 30 min at ∼1 W using a tip sonicator (XL2000-600, Misonix, Newtown, CT, USA) and centrifuged (Sorvall Legend Micro 21R, Thermo Scientific, Waltham, MA, USA) to obtain a suspension of small unilamellar vesicles (SUV). The SUV suspensions were then incubated onto the ODTMS-functionalized solid substrates overnight (Fig. 1). After thorough pipetting to remove excessive SUVs, the solution was replaced with fresh 10 mM Tris–HCl buffer solutions (pH = 7.4) containing designated metal ions (e.g., 100 mM NaCl, 100 mM NaCl + 1 mM CaCl₂, or 100 mM NaCl + 1 mM CdCl₂) by exchanging the solutions at least 10 times of the initial volume using a pipette. The lateral average distance between the lipopolymer molecules, 〈d〉 = 3.6 nm, was calculated from eqn (1), using the cross-sectional area of the single phospholipid membrane A_lipid ≈ 0.6 nm² and the molar fraction of lipopolymers χ_lipo = 0.05.

Total flavonoid content was determined by aluminum chloride colorimetric assay (Zhishen et al., 1999 (link)). Total flavonoid content was extracted from 300 mg of frozen ground basil and 1.5 ml of methanol/H₂O_/acetone (60:30:10 v/v/v) in an ultrasonic bath (Branson 2800, Richmond, VA, United States) for 15 min. Samples were centrifuged at 15,000 RCF (Sorvall Legend Micro 21R, Thermo Fisher Scientific, Waltham, MA, United States) at 4°C for 10 min, and the supernatant was collected. Catechin was used as a quantifying standard. In a 3-ml cuvette, 50 μL of the extracted sample was mixed with 1.95 ml water and 75 μL of 5% NaNO₂. After 6 min 150 μL of 10% AlCl₃ was added and after another 5 min, 500 μL of 1 M NaOH was added. The absorbance was measured at a wavelength of λ = 250 nm in a spectrophotometer (Genesys 50, Thermo Fisher Scientific, Waltham, MA, United States) against a blank. Data was expressed on the base of dry weight as mg/g DW.

Hydrogen peroxide (H₂O₂) was determined according to Junglee et al. (2014) (link) with some modifications. H₂O₂ was extracted from 0.1 g of frozen ground basil leaves with 0.4 ml of 0.1% TCA, 0.4 ml of potassium phosphate buffer (pH 7.6), and 0.8 ml of potassium iodide. After incubation for 10 min at 4°C, the samples were centrifuged at 15,000 RCF (Sorvall Legend Micro 21R, Thermo Fisher Scientific, Waltham, MA, United States) at 4°C for 10 min, and the supernatant was collected. Samples were measured in UV-cuvettes at a wavelength of λ = 350 nm in a spectrophotometer (Genesys 50, Thermo Fisher Scientific, Waltham, MA, United States) against the blank. For quantification, a calibration curve was prepared with H₂O₂ solutions with concentrations from 10 to 400 μmol/L. For each sample, three technical replicates were prepared. Data were expressed on the base of dry weight as mg/g DW.