Silver wire

Tofacitinib citrate was purchased from CSN Pharm (Arlington Heights, IL, U.S.A). Phosphate buffered saline, pH 7.4 (PBS, 10X), sodium phosphate dibasic, orthophosphoric acid, and silver wire (0.5 mm diameter, 99.99%) were obtained from Fisher Scientific (Fair Lawn, NJ, U.S.A). HPLC grade acetonitrile and methanol were procured from Pharmco-Aaper (Brookfield, CT, U.S.A). Polyvinyl alcohol (PVA 26-88 EMPROVE® exp Ph Eur, USP, JPE) and carboxymethyl cellulose sodium salt (CMC low viscosity CAS 9004-32-4) were obtained from Sigma Aldrich (St. Louis, MO, U.S.A). Silver chloride electrodes (2 mm x 4mm) were purchased from A-M systems (Sequim, WA, U.S.A.). Staining solutions, namely methylene blue and Fluoresoft (0.35%), were procured from Eastman Kodak Co. (Rochester, NY, U.S.A) and Holles Laboratories Inc. (Cohasset, MA, U.S.A), respectively. Full-thickness human skin tissue was procured from the National Disease Research Interchange (NDRI) with support from NIH grant U42OD11158.

Dopamine (99%), uric acid (99%), ammonium chloride (99.5%), potassium chloride (99.5%) and methanol (99%) were obtained from Sigma Aldrich (St. Louis, MO, USA). Pure water was purchased from Wahaha Company (Hangzhou, Zhejiang, China). Silver wire (diameter 0.3 mm) was obtained from Alfa Aesar (Shanghai, China) and used as an Ag electrode. The Ag/AgCl electrode was made after electro-deposition of the Silver wire in saturated KCl solution for 3 h. All chemicals were of analytical grade or higher and were used as received.

All electrochemical procedures were carried out with Reference 600+ potentiostat (Gamry Instruments), using sterile 12-well plates (VWR) as the container for electrolytes that were maintained at 37 °C temperature throughout all procedures. A platinum wire was used as counter electrode (99.95% purity, Alfa Aesar), whereas we prepared an Ag/AgCl pseudoreference electrode by treating a silver wire (99.9% purity, Alfa Aesar) in 10% sodium hypochlorite solution (FF-Chemicals) for 45 minutes. We did not deareate the electrolyte solutions in order to recapitulate the real system where biological samples are measured.
All solutions were freshly prepared prior to being used, unless otherwise stated.

DPPH (2,2-diphenyl-1-picrylhydrazyl), and BDPA (α,γ-bisdiphenylene-β-phenylallyl) complex with benzene (1:1) were obtained from Sigma-Aldrich of Merck (Amsterdam, The Netherlands). Mn:CaO was obtained from Alfa Aesar of Fisher Scientific (Landsmeer, The Netherlands) as calcium oxide 99.95% (metals basis). Silver wire was from Alfa Aesar as soft, annealed Silver wire, 0.25 mm in diameter, 99.9% (metals basis). The standard X-band spectrometer is a Bruker EMXplus (Bruker Physik AG, Karlsruhe, Germany). All hardware for its conversion into a broadband spectrometer is detailed in Section 3. Used software was written in LabVIEW (2020) and is given in Supplementary Materials. For proper operation, the BB-Tuner program requires (free) downloading from the NI site and installing of the driver for the NI USB-5681 power meter. The Z-Calculator, for resonator design, does not require additional software.

CV examinations were performed to investigate the electrochemical window of the ChCl-2Urea-Water systems by an electrochemical workstation (CHI650D, Shanghai Chenhua Device Company, China) equipped with a typical three-electrode cell at a scan rate of 5 mV/s. A glassy carbon (GC) microelectrode (0.0707 cm²) and a platinum gauze (10 × 10 mm²) were used as working and counter electrode respectively, and a silver wire (99.9%, Alfa Aesar) inserted in a separated fritted glass tube containing the same IL as the bulk was used as reference electrode. All the electrodes were rinsed and dried before each measurement.