▎ 摘　　要

NOVELTY - Preparing nitrogen-doped graphene mark sensor involves taking glass carbon electrode having diameter of 4mm with aluminum oxide polishing powder, grinding and cleaning with ultra-pure water. The 3-8 mu L of 0.5-2mg/mL gold-silver hetero-alloy liquid is drip to electrode surface and dried at room temperature to form film. The 6 mu L environmental estrogen antibody, and 6 mu L of 0.5-2.5% bovine serum albumin solution are added to non specific active site of electrode, washed with ultra-pure water and placed in refrigerator at 4 degrees C, and then dried by airing. USE - Method for preparing nitrogen-doped graphene mark sensor used for preparing nitrogen doped graphene and environmental estrogen antibody as Ab-N-GS (claimed). ADVANTAGE - The method enables to prepare nitrogen-doped graphene mark sensor, which significantly improves sensitivity, extends linear range and has great significance for detection and analysis of environmental estrogen. DETAILED DESCRIPTION - Preparing nitrogen-doped graphene mark sensor involves taking glass carbon electrode having diameter of 4mm with aluminum oxide polishing powder, grinding and cleaning with ultra-pure water. The 3-8 mu L of 0.5-2mg/mL gold-silver hetero-alloy liquid is drip to electrode surface and dried at room temperature to form film. The 6 mu L environmental estrogen antibody, and 6 mu L of 0.5-2.5% bovine serum albumin solution are added to non specific active site of electrode, washed with ultra-pure water and placed in refrigerator at 4 degrees C, and then dried by airing. The 6 mu l of 0.003-5ng/mL series of different concentration of environmental estrogen antigen standard solution is dripped in electrode surface, washed with ultra-pure water and placed in refrigerator at 4 degrees C, and then dried by airing. The 6 mu L nitrogen doped graphene and environmental estrogen antibody is dripped as Ab-N-GS on electrode surface, washed with ultra-pure water, and placed in refrigerator at 4 degrees C, and then dried by airing. INDEPENDENT CLAIMS are included for: (1) a method for preparing gold-silver heterogeneous alloy, which involves taking 0.001-1mL of 0.05-0.1mol/L chloroauric acid, 0.01-0.05mL of 0.5mol/L silver nitrate, and 0.1-5mL of 0.1-3.5mol/L polydiallyldimethylammonium chloride, adding in 20-200mL ethylene glycol solution, and mixing uniformly to obtain mixed solution; and reacting obtained mixed solution at 60-185 degrees C for 20-100 hours to obtain solid, washing obtained solid with ultra-pure water for 3 times, and subjected to centrifugation at 10000-15000 revolutions per minutes, and subjected to vacuum drying in vacuum drying box at 35-55 degrees C for 2-24 hours to obtain final alloy; and (2) a method for preparing nitrogen doped graphene and environmental estrogen antibody Ab-N-GS, which involves weighing 20-100mg graphene oxide and dispersing in 30-100mL ultra-pure water, and adding 50-300mL N,N-dimethylformamide and subjected to ultrasonic shaking for 0.5-5 hours to obtain mixed liquid; reacting obtained mixed liquid at 130-160 degrees C for 0.5-5 hours, and subjected to centrifugation at 8000-10000 revolutions per minutes for 10-30 minutes to obtain solid; drying obtained solid at below 40-60 degrees C for 12-48 hours to obtain nitrogen doped graphene as N-GS; adding 0.1-0.5g N-GS in 5-15ml anhydrous alcohol and 0.1-3mL aminopropyl triethoxysilane and is placed at 50-85 degrees C for 0.5-5 hours under relux conditions, and subjected to centrifugation at 8000-10000 revolutions per minutes for 10-30 minutes to obtain solid, and drying obtained solid at below 40-60 degrees C for 12-48 hours to obtain aminated nitrogen doped graphene; dispersing obtained aminated N-GS in 10-100mL ultra-pure water and 0.01-10mL glutaraldehyde and 0.01-10mL of 100 mu g/mL environmental estrogen antibody, and oscillating at room temperature for 12 hours to obtain final product.