▎ 摘　　要

NOVELTY - Preparation of a micro-enzyme reactor based on magnetic functionalized graphene oxide involves firstly, loading iron oxide (Fe3O4) magnetic nanoparticles on the surface of graphene oxide by using a one-step in-situ synthesis method to prepare a graphene oxide/Fe3O4 nanocomposite material, secondly, fixing acetylcholinesterase on the surface of the graphene oxide/Fe3O4 through action of pi-pi, hydrogen bonds and water repelling and the like, and fixing a graphene oxide/Fe3O4/acetylcholinesterase compound inside a polydimethylsiloxane microchip channel. USE - The method is useful for preparing micro-enzyme reactor based on magnetic functionalized graphene oxide used in pesticide detection (claimed). ADVANTAGE - The micro-enzyme reactor which is prepared based on a graphene oxide/Fe3O4/acetylcholinesterase composite material is rapid in action, simple to operate and good in reproducibility. DETAILED DESCRIPTION - Preparation of a micro-enzyme reactor based on magnetic functionalized graphene oxide involves: (1) using Hummers method for preparing oxidized graphite alkene: 0.5 g graphite powder and 0.5 g of sodium nitrate (NaNO3) are added to a solution of 23 ml 18 mol/L sulfuric acid (H2SO4), under ice bath slowly adding 3 g potassium permanganate (KMnO4), fully stirring and mixing uniformly, reacting at 35 degrees C water bath for 1 hour, obtaining a grey brown paste, adding 40 ml of water, stirring for 30 minutes at room temperature, and adding water to dilute to 140 ml, gradually adding water and 3 ml 30% hydrogen peroxide (H2O2), deep brown color yellow cause bright spot, filtering the product, cleaning the product with super-pure water where the upper layer clear liquid is neutral, centrifuging at 12000 rpm for 2 minutes, the centrifugal product is dispersed in ultrapure water, and centrifuging at 8000 rpm for 2 minutes, and dispersing the centrifugal product in ultrapure water, performing ultrasonic treatment for 2 hours to obtain graphene oxide solution; (2) preparing iron oxide (Fe3O4) nanoparticles (NPs) functionalized graphene oxide nanomaterial: taking 40 mg graphene oxide dissolved in 20 ml ultrapure water for 30 minutes, completely dissolving graphene oxide, heating to 50 degrees C, adding 216 mg of iron chloride hexahydrate (FeCl3.6H2O) and 80 mg of iron chloride tetrahydrate (FeCl2.4H2O), ultrasonic treatment for 20 minutes, stirring under the condition of adding 1 ml hydrated ammonia (NH3.H2O), stirring for 40 minutes, cooling to room temperature, using magnet to graphite oxide/Fe3O4, and washing using super pure 3 times; (3) preparing oxidized graphite alkene/Fe3O4/acetylcholinesterase: adding 4 mg/ml of oxidized graphite alkene/Fe3O4 and 0.2 mg/ml to phosphate buffer solution, reacting for 24 hours at room temperature, using magnet to separate product and by super-pure water to wash for 3 times, adding graphite oxide/Fe3O4/acetylcholinesterase compound dispersed in the super-pure water, preserving at 4 degrees C for further use; (4) preparing the micro-enzyme reactor: fixing a graphene oxide/Fe3O4/acetylcholinesterase compound inside a polydimethylsiloxane (PDMS) microchip channel, washing PDMS chip separation channel with super-pure for 10 minutes, the upper and lower two sides of the chip separation channel are respectively placed with a diameter of 6 mm in permanent magnet by a vacuum pump to 4 mg luteinizing 1 ml graphite/Fe3O4/acetylcholinesterase compound into the separation channel for 10 minutes, controlling external magnetic field under the action of oxidized graphite alkene/Fe3O4/acetylcholinesterase compound fixed on the chip separation channel, using phosphate buffer solution to wash the separation channel for 5 minutes, and storing in the refrigerator for 2 hours.