Haucl4 4h2o

Glucose Oxidase from Aspergillus niger (GOD, EC 1.1.3.4, 100–250 U/mg) was purchased from Sigma-Aldrich Co. (Saint Louis, MO, USA). Graphene oxide (GO, 1 mg/mL, solvent: water) was purchased from Xianfeng NANO material Tech Co. Ltd. (Nanjing, China). HAuCl₄·4H₂O and pyrrole monomer were purchased from J&K Scientific Ltd. (Beijing, China). Glucose, ascorbic acid, 4-acetamidophenol and uric acid were purchased from Aladdin Industrial Inc (Shanghai, China). Phosphate-buffered saline (0.1 M PBS, pH 7.0) buffer was employed as a supporting electrolyte. All electrochemical experiments were performed in PBS at room temperature, approximately 25 °C.

All of the reagents were of analytical grade and used without further purification. Hydrogen peroxide (30%) was purchased from Guangzhou Chemical Reagent Factory (Guangzhou, China). Graphene oxide was purchased from Nanjin Xianfeng NANO material Tech Co., Ltd. (Shanghai, China). HAuCl₄·4H₂O and pyrrole monomer were purchased from J & K Scientific Ltd. (Beijing China). Alumina (diameter 0.1 and 0.05 μm) was purchased from Chen Hua Instruments (Shanghai, China). All experiments were performed at room temperature, approximately 25 °C.