Phosphorous oxychloride

The 4-methoxybenzoic acid, pyridine-2,6-dicarbaldehyde, phosphorous oxychloride, carbohydrazide, isocyanate and isothiocyanates, Hydrazine hydrate (80%), TEA, CS₂, KOH, sodium hydrogen carbonate, and glacial acetic acid were purchased from Sigma-Aldrich, Darmstadt, Germany. The chloride salts of the transition metals were obtained from Aldrich and Alfa Aesar. Ethanol, mEthanol, chloroform, deionized water, acetonitrile, dimethyl sulfoxide, petroleum ether, ethyl acetate, n-hexane, toluene (Samchun Chemicals, Seoul, Korea), H₂SO₄, acetic acid, and HCl (Jin Chemical and Pharmaceutical Co. Ltd., Seoul, Korea) were used in this experiment. Urease from jack bean (EC 3.5.1.5), Thio-urea, sodium nitroprusside, and active chloride were purchased from Sigma (St. Louis, MO, USA). Stock solutions of the reducing substrates were prepared in phosphate buffer (20 mM, pH 6.8).

1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS, C₁₆H₁₉F₁₇O₃Si), tetraethyl orthosilicate (TEOS), anhydrous diethyl ether, phosphorous oxychloride, fluorinated alkyl-polyethylene glycol (FA-PEG, M_w ≈ 600), trimethylamine, oil red, oil blue, and oil green were purchased from Sigma-Aldrich and used as received. Ammonium hydroxide (28%) and ethanol were purchased from Chem-Supply Pty Ltd. Commercial cotton fabric (plain weave, 160 g m⁻², thickness ≈ 510 μm) was obtained from local store.