2 n morpholino ethanesulphonic acid

Poly(vinyl alcohol) (PVA, M_w ~195000), maleic acid (MA) and ascorbic acid were purchased from Aladdin Reagent Company (Shanghai, China). Chloroplatinic acid hexahydrate (H₂PtCl₆∙6H₂O) and palladium chloride (PdCl₂) were bought from Shanghai Chemical Reagent Co., Ltd. (Shanghai, China). Alcohol oxidase enzyme (AOX) extracted from Pichia pastoris (10-40 units/mg protein), glucose oxidase (GOX), 2-(N-morpholino)-ethanesulphonic acid (MES, ≥99%), potassium acetate (KAc) and Pluronic F-127 were supplied by Sigma Chemical Co. (St. Louis, MO, USA). Hydrogen peroxide (H₂O₂, 30%), hydrochloric acid and sulfuric acid were obtained from Beijing Chemical Works (Beijing, China). 3,3,5,5-tetramethylbenzidine (TMB, >99.0%) was purchased from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China). The double deionized water (hereinafter denoted as H₂O for short) was used in all experiments (Millipore water purification system, Merck, Darmstadt, Germany). All the chemicals and reagents were used without further purification.

Acrylamide (Aam), Methacrylic acid (MAA), N-tert-butylAcrylamide (TBAm), N,N′-methylenebisAcrylamide (BIS), N,N,N′,N′-tetramethylethylenediamine (TEMED), ammonium persulfate (APS), sodium dodecyl sulfate (SDS), sodium dihydrogen phosphate, sodium monohydrogen phosphate, sodium chloride, hydrochloric acid, Trizma^® base, 2-[N-morpholino]ethanesulphonic acid (MES), N-(3-dimethylaminopropyl)-N′-ethyl-carbodiimide hydrochloride (EDC), N-hydroxysulfosuccinimide (NHS), sodium acetate, Tween-20, ethanol, bovine serum albumin (BSA), k-casein, horseradish peroxidase (HRP), and 3,3′,5,5′-tetramethylbenzidine (TMB) were from Sigma-Aldrich (Darmstadt, Germany).