▎ 摘　　要

NOVELTY - Preparing copper-metal-organic frameworks loaded-doped graphene composite material comprises (i) adding 1.5-2.5 mmol copper nitrate trihydrate to the mixed solvent and stirring to dissolve, adding 1-1.5 mmol trimesic acid and continuing stirring for 1-2 hours to form a dispersion, adding the dispersion to a reaction kettle, reacting in an oven at 70-90 degrees C for 16-24 hours, and washing and drying to obtain blue copper-metal-organic frameworks powder after the product is separated, (ii) taking 8-10 mg nitrogen-doped graphene dispersed in 8-12 ml N,N-dimethylformamide solvent and ultrasonic oscillating for 1-2 hours to obtain a nitrogen-doped graphene dispersion liquid, and (iii) taking 0.8-1.2 mg copper-metal-organic frameworks powder and adding nitrogen-doped graphene dispersion liquid to ultrasonically disperse for 1.5-3 hours. USE - The electrode is useful for detecting rutin content in citrus (claimed). ADVANTAGE - The method has high sensitivity, low detection limit, simple operation and quick detection. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) copper-metal-organic frameworks loaded-doped graphene composite material prepared by the above preparation method; (2) preparing the copper-metal-organic frameworks loaded-doped graphene composite modified electrode, comprising (a) ultrasonically dispersing the copper-metal-organic frameworks-supported nitrogen-doped graphene composite material in N,N-dimethylformamide solvent to obtain an electrode modification solution, (b) taking the electrode modification on the surface of the pre-treated glassy carbon electrode, and drying to obtain the nitrogen-doped graphene composite modified electrode supported by copper-metal-organic frameworks, where in the step (a), the dosage ratio of the copper-metal-organic frameworks-loaded nitrogen-doped graphene composite material and the N,N-dimethylformamide solvent is 1 mg:2-4 ml, preferably 1 mg:2 ml, and the amount of electrode modification solution used in the step (b) is 4-8 mu l, preferably 6 mu l; and (3) copper-metal-organic frameworks loaded-doped graphene composite modified electrode prepared by the above mentioned method; and (4) use method of electrode for detecting rutin content in citrus, comprising using the square wave voltammetry for the determination comprises a forming three-electrode system by using copper-metal-organic frameworks loaded nitrogen-doped graphene composite modified electrode as working electrode, using platinum electrode as auxiliary electrode and using saturated calomel electrode as reference electrode, connecting the three-electrode system to the electrochemical workstation, preparing standard solution and actual sample solution to be tested, using the square wave voltammetry to determine the peak current value of rutin oxidation in different standard solutions, and obtaining a linear equation based on the relationship between the peak current value of rutin oxidation and its concentration, using square wave voltammetry to determine the peak current value of rutin oxidation in the sample solution to be tested, obtaining the concentration of rutin according to the linear equation, and obtaining the content of rutin in the actual sample where the linear equation of rutin in the range of 0.01-0.3 mu mol/l is ip is 6.9078c+0.1653, R2 is 0.969, in the range of 0.3-10 mu mol/l the linear equation is ip is 1.4439c+0.9892, R2 is 0.9892 where c is the concentration of rutin, the unit is mu mol/l, ip is the square wave voltammetry to obtain the oxidation peak current value, the unit is mu A, the detection condition of the square wave voltammetry is B-R buffer with a pH of 6 is a supporting electrolyte, the potential range is 0-1 V, the potential increment is 4 mV, the amplitude is 25 mV, and the frequency is 15 Hz.