▎ 摘　　要

NOVELTY - Method for preparing graphene immobilized enzyme involves (a) preparing graphene oxide powder with activated surface carboxyl group, (b) adding the graphene oxide powder with activated surface carboxyl groups to the aqueous solution containing the crosslinking agent, ultrasonically processing for 20-30 minutes, adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) hydrochloride aqueous solution, stirring to fully chelate the reaction, centrifuging to separate the resulting solids and drying to obtain functionalized graphene oxide modified with surface active groups, and (c) taking 5 mg functionalized graphene oxide powder modified with surface active groups, adding to 5 ml phosphate-buffered saline (PBS) buffer, ultrasonically processing, adding dihydroxyphenylalanine (DOPA) decarboxylase-containing PBS buffer and functionalized graphene oxide in the mixture, reacting, centrifugally separating, washing, freeze-drying and storing to obtain product. USE - The method is useful for preparing graphene immobilized enzyme used for catalyzing DOPA decarboxylation to produce dopamine (claimed). ADVANTAGE - The method prepares graphene immobilized enzyme through synergistic catalytic effect with improved stability and reproducibility, is applied to the field of enzyme decarboxylation, is performed simply in an environmentally-friendly manner with high conversion rate, and is especially suitable for immobilization of decarboxylase. DETAILED DESCRIPTION - Method for preparing graphene immobilized enzyme involves (a) taking 1 mg/ml graphene oxide (GO) aqueous dispersion, adding sodium hydroxide and sodium chloroacetate solids to keep the concentration of sodium hydroxide and sodium chloroacetate at 3-4 mg/ml, performing ultrasonic reaction in a water bath for 1-2 hours, after neutralizing with dilute hydrochloric acid, washing with deionized water to neutrality, freeze-drying to obtain graphene oxide powder with activated surface carboxyl group and maintaining airtight, (b) adding the graphene oxide powder with activated surface carboxyl groups to the aqueous solution containing the crosslinking agent, ultrasonically processing for 20-30 minutes, adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) hydrochloride aqueous solution to maintain final concentration of EDC at 1.2-3 mg/ml, stirring vigorously at room temperature for 12-16 hours to fully chelate the reaction, centrifuging to separate the resulting solids repeatedly with deionized water until the pH of the washing solution is neutral and drying for 15-24 hours in a vacuum environment to obtain functionalized graphene oxide modified with surface active groups, and (c) taking 5 mg functionalized graphene oxide powder modified with surface active groups, adding to 5 ml phosphate-buffered saline (PBS) buffer, ultrasonically processing for 5-10 minutes, adding dihydroxyphenylalanine (DOPA) decarboxylase-containing PBS buffer to maintain the initial concentration of DOPA decarboxylase and functionalized graphene oxide in the mixture at 0.2-0.6:1, reacting at 4 degrees C for 3-5 hours, centrifugally separating, washing to obtain graphene immobilized enzyme catalyst particles, freeze-drying and storing at -20 degrees C to obtain product. An INDEPENDENT CLAIM is included for use of the graphene immobilized enzyme to catalyze the decarboxylation of DOPA to produce dopamine.