Maltose

All chemicals were of analytical grade and used as received without further purification. 3, 3′, 5, 5′-Tetramethylbenzidine (TMB) was purchased from BIOSHARP company, glucose oxidase (GOx, from Aspergillus niger, ≥100 U/mg), and DMPO (5, 5-dimethyl-1-pyrroline N-oxide) were purchased from Sigma-Aldrich (St. Louis, USA). Glucose, fructose, lactose, maltose, cholesterol, inositol, ascorbic acid, vitamin B1, and vitamin B9 were purchased from Beijing Chemical Reagent Company (Beijing, China). H₂O₂ and other regeants were obtained from Boyue Biological Reagent Co. (Harbin, China).

All chemicals were used as received without further purification. Ferric chloride hexahydrate (FeCl₃.6H₂O), 5, 10, 15, 20-tetra (4-(imidazol-1-yl)phenyl) porphyrindine (TIPP), polyvinylpyrrolidone (PVP, Mw~4000) and tetraethyl orthosilicate (TEOS) were purchased from Aladdin Company. Ethanol (CH₃CH₂OH, 99.7%), N, N-dimethylformamide (DMF, AR), α,α‘-Dibromo-p-xylene, sodium sulfate anhydrous (Na₂SO₄), sodium hydroxide (NaOH), hydrogen chloride (HCl, 37%) were purchased from Sinopharm Chemical Reagent Co., Ltd. Chloroauric acid (HAuCl₄·4H₂O) was purchased from Sigma-Aldrich. Dopamine HCl was purchased from Beijing HWRK Chem Co., Ltd. 3,3’,5,5’-tetramethylbenzidine (TMB) and PBS were gotten from Sangon Biotech (Shanghai) Co., Ltd. Glucose, fructose, sucrose, L-cysteine, ascorbic acid, dopamine, uric acid, and maltose were purchased from Beijing Chemical Reagent Company. Deionized (DI) water from Milli-Q System (18.2 MΩ·cm, Millipore, Billerica, MA) was used in all experiments.