▎ 摘　　要

NOVELTY - A graphene oxide nano silver grain enhanced Raman substrate preparing method involves dispersing graphene oxide in deionized water ultrasonically to obtain graphene solution, dissolving polyethylenimine in deionized water to obtain polyethylenimine solution. The graphene solution is mixed with polyethylenimine solution, centrifuged, and washed to obtain composite product, followed by heating silver nitrate in water, adding sodium citrate solution and stirring, cooling, and cleaning ultrasonically to obtain silver sol solution. The composite product is placed in the sol solution, and washed. USE - Method for preparing graphene oxide nano silver grain enhanced Raman substrate. DETAILED DESCRIPTION - A graphene oxide nano silver grain enhanced Raman substrate preparing method involves dispersing graphene oxide in deionized water ultrasonically to obtain graphene solution, dissolving polyethylenimine in deionized water to obtain polyethylenimine solution. The graphene solution is mixed with polyethylenimine solution ultrasonically to obtain mixed solution, which is centrifuged, and washed to obtain graphene oxide and polyethylenimine composite product, followed by heating silver nitrate in deionized water, adding sodium citrate solution and stirring, cooling naturally, and cleaning ultrasonically to obtain silver sol solution. The composite product is placed in the sol solution, and washed with deionized water to obtain a finished product.