3 glycidoxypropyl trimethoxysilane

All chromatographic analyses were performed using the Shimadzu Nexera UHPLC system (Kioto, Japan). This chromatograph is equipped with a binary solvent delivery system (LC-30AD), an autosampler with a 20 µL volume loop (SIL-20AC), a column thermostat (CTO20AC), and a diode-array UC-detector (SPD-M20A). LabSolution LC/GC 5.65 software (Shimadzu, Kioto, Japan) was used to collect and process data and control the apparatus. Acetonitrile (ACN) (HPLC Grade) and methanol (MeOH) (HPLC Grade) were purchased from Sigma–Aldrich (Steinheim, Germany). Packaging solvents, isopropanol, and methanol were purchased from J.T. Baker, Deventer, the Netherlands. Water was prepared with a Milli-Q Water Purification System (Millipore Corporation, Bedford, MA, USA). Standards of nucleosides—adenosine, guanosine, uridine—were obtained from Applichem (Darmstadt, Germany). Non-polar compounds—naphthalene, benzene, phenanthrene, caffeine, theophylline, and theobromine—were obtained from Sigma–Aldrich (St. Louis, MO, USA). For the synthesis of stationary phases (3-glycidoxypropyl) trimethoxysilane, decanol, octadecanol, cholesterol, benzyl alcohol, and phosphorus chloride were used, which were purchased from Alfa Aesar (Karlsruhe, Germany). Haskel (Burbank, CA, USA) laboratory equipment and packing pump were used to pack the stationary phases into 125 × 4.6 mm long empty columns.

Ethylene glycol (≥99%), 4-Dodecylbenzensulfonic acid (≥95%), Acetic acid (99.7%), bovine serum albumin (BSA), chitosan, glutaraldehyde (25% wt), hydrogen peroxide (H₂O₂, 30% wt in H₂O), L-(+)-lactic acid (≥98%), phosphate buffer solution (PB, 0.1 M), poly (vinyl chloride) (low molecular weight) (PVC), and tetrahydrofuran (anhydrous, 99.9%) were purchased from Sigma-Aldrich (St. Louis, MO). (3-Glycidoxypropyl)trimethoxysilane (97%) was purchased from Alfa Aesar (Tewksbury, MA). Lactate oxidase (106 U mg⁻¹) was purchased from Toyobo Corp. (Osaka, Japan). Phosphate buffered saline (PBS, 1X sterile) was purchased from VWR International (Philadelphia, PA). 500FPC Kapton film was purchased from American Durafilm (Holliston, MA). Clevios PH 1000 conductive polymer was purchased from Heraeus Precious Metals North America (Conshohocken, PA). Carbon Graphite Ink containing Prussian Blue (P/N C2070424P2) was purchased from Gwent Group (Pontypool, UK).
PEDOT:PSS stock solution was mixed immediately before use, combining 40 mL Clevios PH 1000 conductive polymer with 10 mL Ethylene glycol, 8 drops of 4-Dodecylbenzensulfonic acid, and 500 µL of (3-Glycidoxypropyl)trimethoxysilane. The mixture was then sonicated for ten minutes and deposited on substrates the same day.