▎ 摘　　要

NOVELTY - A graphene coated zinc oxide three-dimensional composite catalyst comprises 66-70 wt.% zinc oxide, and graphene coated zinc oxide in three-dimensional fusiform. USE - Graphene wrapped zinc oxide three-dimensional composite catalyst. ADVANTAGE - The product has high sensitivity and good stability, and constructs electrochemical sensor on the surface of glassy carbon electrode directly applied to chloramphenicol sensitive detection with detection lower limit to 0.5 mu m. The method is simple, and has fast operation. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparation of graphene coated zinc oxide three-dimensional composite catalyst comprising adding zinc foil into graphene oxide water solution, hydrothermal reacting at 80-100 degrees C for 0.5-1 hour, ultrasonically vibrating, washing, and drying; and (2) preparation of electrochemical sensor for detecting chloramphenicol comprising ultrasonically dispersing and mixing graphene coated zinc oxide three-dimensional composite catalyst into ethanol to obtain dispersion liquor, transferring into glassy carbon electrode active surface, drying to obtain graphene coated zinc oxide three-dimensional composite catalyst modified glassy carbon electrode, differential pulse volt-ampere analyzing with graphene coated zinc oxide three-dimensional composite catalyst modified glassy carbon electrode as working electrode, saturated calomel electrode as reference electrode, platinum wire as auxiliary electrode and test base solution as phosphate buffer solution, constructing standard working curve, and calculating chloramphenicol concentration in sample.