▎ 摘　　要

NOVELTY - Method for preparing dual-modal contrast agent involves providing graphene quantum dots and a first solvent, dissolving the graphene quantum dots in the first solvent, ultrasonically treating to form a first mixed solution, adding a second solvent to the first mixed solution to form a second mixed solution, subjecting the second mixed solution to a solvothermal reaction to obtain a third mixed solution, adding gadolinium inorganic salt to the third mixed solution to obtain a fourth mixed solution, subjecting the fourth mixed solution to a solvothermal reaction to obtain a fifth mixed solution, performing dialysis and purification on the fifth mixed solution and freeze-drying to obtain a dual-modal contrast agent. USE - The method is useful for preparing dual-modal contrast agent used in nuclear magnetic resonance imaging technology and fluorescence imaging technology. ADVANTAGE - The method prepares dual-modal contrast agent which has high relaxation rate, controllable structure and high yield and is simple.