Sulfuric acid 95 98 h2so4

Ethanol analytical grade 96% (v/v), 6-mercaptohexanoic acid (6-MHA), cysteamine (CYST), sodium acetate (NaAc), acetic acid (CH₃COOH), sodium hydroxide 97% (NaOH), sodium phosphate (Na₂HPO₄/NaH₂PO₄), potassium ferricyanide (FeCN), and sulfuric acid 95–98% (H₂SO₄) were purchased from Sigma-Aldrich. 100 mM sodium acetate/phosphate buffer solutions were prepared by mixing NaAc, Na₂HPO₄/NaH₂PO₄, and acetic acid in an appropriate ratio. All solutions were prepared with Milli-Q water (18.2 MΩ cm). Indium-tin oxide (ITO) slides (25 × 75 mm) were purchased from Osilla (osilla.com). BOD from Myrothecium verrucaria (Mv BOD) was a gift from Amano Enzymes Inc. (Nagoya, Japan). LAC from Thermus Thermophilus HB27 (Tt LAC) was expressed and purified in our lab according to Hitaishi et al. (2020 (link)).

All the chemicals and reagents were purchased from: Merck (Darmstadt, Germany) (ethanol absolute, Folin-Ciocalteu reagent, gallic acid, sodium carbonate (Na₂CO₃)), Sigma-Aldrich (St. Louis, MO, USA) (sulfuric acid 95–98% (H₂SO₄), potassium peroxodisulfate, acetylthiocholine iodide (ATCI), acetylcholinesterase (AChE), 5,5′-dithio-bis(2-nitrobenzoic acid) (DTNB), galanthamine hydrobromide), Sigma (St. Louis, MO, USA) 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS^•+)), Carlo Erba Reagents (Val-de-Reuil, France) (hexane, petroleum ether, dimethyl sulfoxide (DMSO)), Lab-Scan (Dublin, Ireland) (chloroform), Panreac (Barcelona, Spain) (sodium sulfate (Na₂SO₄) anhydrous), Fisher Scientific (Loughborough, UK) (methanol high-performance liquid chromatography (HPLC)-grade, hydrochloric acid 37% (HCl)), Glentham Life Sciences (Corsham, UK) (2,2-diphenyl-1-picrylhydrazyl (DPPH^•)), Acros Organics (New Jersey, USA) (trolox) and Lachner (Neratovice, Czechia) (sodium hydroxide micropearls (NaOH)), the fatty acids methyl ester (FAME) reference standard mixture 37 (standard 47885) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Sesame oil and linseed oil were supplied by Sigma-Aldrich (St. Louis, MO, USA, tested quality according to Ph. Eur.), while the olive oil (variety Kalamon) was obtained from a Greek producer (Sparti, Peloponnese, Greece).