Methyl 4 nitrobenzenesulfonate

KCl, Na₂SO₄, 2-(N-morpholino)ethanesulfonic acid (MES), tris(hydroxymethyl)aminomethane (Tris), EGTA, hexane, hexadecane, cytochrome c (Cyt c), decylubiquinone, KCN, sucrose, 3-(N-morpholino)propanesulfonic acid (MOPS), bovine serum albumin (BSA), arachidonic acid (AA), genipin, geniposide, adenine triphosphate (ATP), ammonium phosphate (monobasic, NH₄H₂PO₄), dimethyl sulfoxide (DMSO), sulfo-NHS-acetate (NHS), methyl-4-nitrobenzenesulfonate (MNBS), N-ethylmaleimide (NEM), and diammonium salt of malic acid were purchased from Sigma-Aldrich (Munich, Germany). EDTA, KH₂PO₄, NaN₃, and acetonitrile were purchased from Merck (Darmstadt, Germany). Diphytanoylphosphatidylcholine, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and cardiolipin (CL) came from Avanti Polar Lipids (Alabaster, AL). Chloroform was obtained from Carl Roth (Karlsruhe, Germany).

2-Methyl-2-oxazoline (MeOx), purchased from TCI (Zwijndrecht, Belgium), was dried over KOH for 24 h, distilled over CaH₂ and stored under argon. 2-n-propyl-2-oxazoline (nPrOx) was prepared from butyronitrile and 2-aminoethanol [43 (link),44 (link)], dried over KOH for 24 h, distilled over CaH₂ and stored under argon. Calcium hydride (CaH₂), methyl 4-nitrobenzenesulfonate, dexamethasone were purchased from Sigma-Aldrich (Steinheim, Germany) and used as received. Potassium hydroxide (KOH) was purchased from Mikrochem (Bratislava, Slovakia), methanol from Centralchem (Bratislava, Slovakia). Benzonitrile (Sigma-Aldrich, Steinheim, Germany) was distilled over P₂O₅ and stored under argon. Diethyleter and ethanol (p.a. 96%) were purchased from Centralchem (Bratislava, Slovakia). Phosphate-buffered saline (PBS) was purchased from Sigma-Aldrich (Dulbecoo´s PBS, Steinheim, Germany).

Methyl 4-nitrobenzenesulfonate, diisopropylamine, allyl bromide and butyllithium in hexanes (2.5 M) were purchased from Sigma-Aldrich (Steinheim, Germany). 2-Methyl-2-oxazoline (MeOx) provided by TCI (TCI Europe N.V., Belgium) was dried over KOH for 48 h, distilled over CaH₂ under the reduced pressure and stored under argon. Acetonitrile (J.T. Baker, Netherlands, HPLC grade) and dichloromethane (Lach-Ner, Czech Republic) were distilled over CaH₂ and stored on molecular sieves under argon. Tetrahydrofuran (Centralchem, Slovakia) was distilled from sodium benzophenone ketyl prior to use. Isopropanol (Penta s.r.o., Czech Republic) and chloroform (Lach-Ner, Czech Republic) were used as received. For washing of samples before and after plasma treatment deionized water was used.
Polytetrafluoroethylene (PTFE) sheets with a thickness of 1 mm provided by Goodfellow Cambridge Ltd. were used as a substrate material for the deposition of the poly(2-oxazoline) layer. Before experiments, PTFE sheets were cut into different shapes appropriate for individual measurement techniques (squares with dimensions of 1 × 1 cm², rectangles with dimensions of 1 × 2.5 cm², circular samples with a diameter of 15 mm). Before all experiments, PTFE samples were ultrasonically cleaned in isopropanol and distilled water, in both solvents 2 times for 10 min and then dried in the nitrogen flow.