▎ 摘　　要

NOVELTY - A silver-Prussian blue supported nitrogen-doped graphene composite material preparing method involves adding 0.01-0.02 g of potassium ferricyanide to 2-3 mL of hydrochloric acid, 8-15 mL of deionized water, 3-6 mL of N, N-dimethylformamide, reacting at 70-90 degrees C, and separating and washing the product to obtain Prussian blue, dissolving Prussian blue in 10-30 mL of deionized water, adding 0.5-1.0 g of glucose, stirring for 10-40 minutes to obtain a Prussian blue dispersion, adding a silver ammonia solution to the Prussian blue dispersion at a rate of 0.5-2 mLmin-1, heating at 30-40 degrees C for 20-40 minutes in a water bath, and allowing to stand for 0.5-2 hours, separating and washing the product to obtain a silver-Prussian blue material, adding 0.1-0.3 mg of silver-Prussian blue material to 1-3 ml of N,N-dimethylformamide dispersed in nitrogen-doped graphene at a concentration of 0.5-2 mg/mL, sonicating for 20-40 minutes, centrifuging and drying to obtain the finished product. USE - Method for preparing a silver-Prussian blue supported nitrogen-doped graphene composite material for rapid detection of sodium nitrite in food. ADVANTAGE - The method enables preparing a silver-Prussian blue supported nitrogen-doped graphene composite material with wide detection range, low detection limit in simple manner. DETAILED DESCRIPTION - A silver-Prussian blue supported nitrogen-doped graphene composite material preparing method involves adding 0.01-0.02 g of potassium ferricyanide to 2-3 mL of concentrated hydrochloric acid, 8-15 mL of deionized water, and 3-6 mL of N, N-dimethylformamide, and carrying out the reaction in a reaction kettle for 16-32 hours, reacting at 70-90 degrees C, and separating and washing the product to obtain Prussian blue, dissolving Prussian blue in 10-30 mL of deionized water, adding 0.5-1.0 g of glucose, stirring for 10-40 minutes to obtain a Prussian blue dispersion, adding a silver ammonia solution to the Prussian blue dispersion at a rate of 0.5-2 mLmin-1, heating at 30-40 degrees C for 20-40 minutes in a water bath, and allowing to stand for 0.5-2 hours, separating and washing the product to obtain a silver-Prussian blue material, adding 0.1-0.3 mg of silver-Prussian blue material to 1-3 ml of N,N-dimethylformamide dispersed in nitrogen-doped graphene at a concentration of 0.5-2 mg/mL, sonicating for 20-40 minutes, centrifuging and drying to obtain the finished product. An INDEPENDENT CLAIM is also included for a silver-Prussian blue supported nitrogen-doped graphene composite material prepared by the method.