▎ 摘　　要

NOVELTY - Graphene-coated cobalt-platinum composite nanomaterial comprises graphene as shell and cobalt-platinum alloy as core-shell structure. It is spherical particle having particle diameter of 3-5 nm. USE - The graphene-coated cobalt-platinum composite nanomaterial is used for MRI, preparing catalyst for catalyzing hydrogen peroxide to generate oxygen or catalyzing peroxide to generate hydroxy, and preparing oxidant, oxidant of strong acid system, and reagent for treating tumor (all claimed). It is used as T2 contrast agent and hydrogen peroxide nanoenzyme. The composite nanomaterial is used for killing tumor cell. ADVANTAGE - The composite nanomaterial has better contrast effect than the same product, strong tumor cell inhibiting effect, and oxidase and peroxidase properties, can resist aqua regia, can exert oxidation effect under the condition of strong acid, and promotes the catalytic generation of more oxygen into the cell and more oxygen to enter into the cell, so as to kill the tumor cell. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the graphene-coated cobalt-platinum composite nanomaterial comprising dispersing gas phase silicon dioxide (SiO2) to obtain solution A, mixing the cobalt salt solution with platinum ion solution, obtaining solution B, mixing solution A and solution B, rotary evaporating, and drying; and grinding the dried mixture into powder, burning in methane (CH4) gas stream and mixing with hydrofluoric acid (HF) solution, and magnetically separating to obtain solid i.e. cobalt-platinum composite nanoparticle wrapped by graphene.