▎ 摘　　要

NOVELTY - Composite material of nano-zinc oxide and reduced graphene oxide is prepared by (i) pretreating nano-zinc oxide by ultrasonically dispersing nano-zinc oxide particles in absolute ethanol, adding 3-aminopropyltriethoxysilane (APTES) to dispersion, refluxing in water bath, centrifuging, washing and drying to obtain pretreated nano-zinc oxide, (ii) heating concentrated sulfuric acid, adding dipotassium persulfate and phosphorus pentoxide to concentrated sulfuric acid, dripping graphite powder, heating and stirring mixture, cooling, diluting mixture with deionized water, washing, and drying to obtain reduced graphene oxide, and (iii) preparing pretreated nano zinc oxide and water into nano zinc oxide suspension, configuring reduced graphene oxide into reduced graphene oxide suspension, mixing nano-zinc oxide suspension and reduced graphene oxide suspension to obtain mixed suspension, dripping mixed suspension on surface of gold electrode, and air-drying. USE - The composite material of nano-zinc oxide and reduced graphene oxide is used for electrochemical detection of dopamine (claimed). ADVANTAGE - The composite material of nano-zinc oxide and reduced graphene oxide improves detection sensitivity and reduces detection limit. DETAILED DESCRIPTION - Composite material of nano-zinc oxide and reduced graphene oxide is prepared by (i) pretreating nano-zinc oxide by ultrasonically dispersing nano-zinc oxide particles in absolute ethanol, adding 3-aminopropyltriethoxysilane (APTES) to dispersion, refluxing in a water bath at 50-90 degrees C, centrifuging, washing and drying to obtain pretreated nano-zinc oxide, where the mass-to-volume ratio of nano-zinc oxide and 3-aminopropyltriethoxysilane (APTES) is (0.1-12):(3-60), (ii) adding concentrated sulfuric acid to a beaker and heating at 80-100 degrees C, adding dipotassium persulfate and phosphorus pentoxide to the concentrated sulfuric acid, dripping graphite powder, heating and stirring the mixture at 80-100 degrees C for 4-8 hours, cooling, diluting the mixture with deionized water, washing the mixture with deionized water by centrifugation to pH of 7, and drying the solid product in air at room temperature (20-25 degrees C) to obtain reduced graphene oxide, where the volume-to-mass ratio of concentrated sulfuric acid, dipotassium persulfate, phosphorus pentoxide and graphite powder is (10-50):(1-8):(3-12):(1-12), and (iii) preparing the pretreated nano zinc oxide obtained in step (i) and water into a nano zinc oxide suspension, configuring the reduced graphene oxide obtained in step (ii) into a reduced graphene oxide suspension with the same mass parts as the nano zinc oxide suspension, stirring and mixing the nano-zinc oxide suspension and the reduced graphene oxide suspension to obtain a mixed suspension, dripping 4-10 mu l mixed suspension on surface of gold electrode, and air-drying to obtain the composite of nano-zinc oxide and reduced graphene oxide material, where the concentration of the nano zinc oxide suspension is 1-15 mg/ml, and the concentration of the reduced graphene oxide suspension is 1-15 mg/ml. INDEPENDENT CLAIMS are included for the following: (1) a method for preparing the composite material of nano-zinc oxide and reduced graphene oxide; and (2) the use of the composite material of nano-zinc oxide and reduced graphene oxide for electrochemical detection of dopamine, which involves placing the composite material in the solution to be tested for electrochemical reduction, when the current has a downward peak, recording the downward change peak of the current and analyzing to obtain a linear concentration curve satisfying that y is equal to -0.26x-1.23, where y is the peak current, x is the concentration of dopamine, R2 is 0.998 and the sensitivity is 260 nA/ mu mol.