▎ 摘　　要

NOVELTY - Graphene-based sandwich immunoassay, comprises contacting sample with multiple of graphene-oxide coated particles, where each having at least one targeting receptor, e.g. the target biological substance, if present, associates with targeting receptor, the graphene-oxide coated particles comprises core particle having surface, graphene-oxide-layer coating core particle, the graphene-oxide layer comprises graphene-oxide nanosheets, graphene-oxide nanosheets being covalently bonded to particle surface, at least one polydopamine polymer coupled with graphene-oxide nanosheets, targeting receptor coupled to at least one polydopamine polymer, and detecting presence of target biological substance in sample by subsequently contacting sample with detection antibody. USE - The method is useful in detecting whether target biological substance is present in sample. ADVANTAGE - The method improves detection sensitivity by 102 and 104 folds. DETAILED DESCRIPTION - Graphene-based sandwich immunoassay, comprises: contacting sample with multiple of graphene-oxide coated particles, where each having at least one targeting receptor, e.g. the target biological substance, if present, associates with targeting receptor, the graphene-oxide coated particles comprises core particle having surface, graphene-oxide-layer coating core particle, the graphene-oxide layer comprises graphene-oxide nanosheets, graphene-oxide nanosheets being covalently bonded to particle surface, at least one polydopamine polymer coupled with graphene-oxide nanosheets, targeting receptor coupled to at least one polydopamine polymer, where the targeting receptor is capable of targeting and binding with target biological substance, if present; and detecting presence of target biological substance in sample by subsequently contacting sample with detection antibody, where the detection antibody is capable of targeting and binding with target biological substance if bound to targeting receptor to yield detectable complex.