Potassium hexacyanoferrate k3 fe cn 6

Graphite powder, dopamine (DA) hydrochloride, L-(+)-ascorbic acid (AA), uric acid (UA), citric acid (CA), glucose, potassium hexacyanoferrate (K₃[Fe(CN)₆]), phosphate buffer saline (PBS, pH 7.4, 0.1 M), and hydrogen tetrachloroaurate (III) (HAuCl₄) were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). All the other chemicals used such as sodium hydroxide (NaOH), sodium nitrate (NaNO₃), sodium carbonate (Na₂CO₃), potassium permanganate (KMnO₄), hydrogen peroxide (H₂O₂), and sulfuric acid (H₂SO₄) were obtained from Duksan Pure Chemicals Co. (Ansan, Korea). All the reagents were analytical grade and were used without further purification. Deionized (DI) water was used throughout the work.

PAMAM dendrimer generation 1.0 solution (PAMAM_G1; [NH₂(CH₂)₂NH₂]:(G = 1); dendriPAMAM(NH₂)8; Mw = 1429.85 g/mol), glutamate oxidase (GluOx; L-glutamate: oxygen oxidoreductase, EC 1.4.3.11, from Coriolus sp., 0.2 U/vial), L-glutamic acid monosodium salt monohydrate (MSG; MW = 187.13 g/mol), polycaprolactone (6-Caprolactone polymer; average Mn = 80,000), glutaraldehyde (25%), formic acid (98–100%), D-glucose (99.5%), ascorbic acid (99%), 3-acetamidophenol (97%), uric acid (99%), L-glycine, L-lysine, L-aspartic acid, potassium hexacyanoferrate (K₃[Fe(CN)₆]), monosodium phosphate (NaH₂PO₄), and potassium chloride (KCl) were purchased from Sigma-Aldrich, St. Louis, MO, USA. Chitosan middle-viscous was purchased from Fluka, Buchs, Switzerland and acetone was provided by Merck, Darmstadt, Germany. The water was used from a Millipore (Burlington, MA, USA) Milli-Q ultrapure water system. Powder tomato soup was purchased from local market to detect MSG in real samples.