▎ 摘　　要

NOVELTY - The method comprises obtaining the graphene oxide, obtaining a positively charged substrate, where the graphene oxide through a static electricity resistance is connected with the substrate and a microcystin antibody and covalently is linked to a donor substrate, and obtaining gold nano particles and mercapto modified single chain DNA compound with the gold nano particles, where: the single-stranded DNA is provided with 12-20 basic groups; and the single chain DNA-gold nanometre compound and microcystin are standard product with different concentrations. USE - The method is useful for detecting microcystin. ADVANTAGE - The method is capable of simply, accurately, rapidly and efficiently detecting the microcystin with high sensitivity and specificity. DETAILED DESCRIPTION - The method comprises obtaining the graphene oxide, obtaining a positively charged substrate, where the graphene oxide through a static electricity resistance is connected with the substrate and a microcystin antibody and covalently is linked to a donor substrate, obtaining gold nano particles and mercapto modified single chain DNA compound with the gold nano particles, where: the single-stranded DNA is provided with 12-20 basic groups, the single chain DNA-gold nanometre compound and microcystin are standard product with different concentrations to obtain standard product receptor complex with the donor substrate and to obtain a portion of an immunoglobulin heavy chain complementary single chain DNA by hatching through antigen-antibody specific reaction to obtain graphene-microcystin antibodytoxin-chain DNA-gold nano-particle composition; and the graphene oxide and the gold nano-particle are fluorescent resonance energy transfer, obtaining a first fluorescence quenching intensity by a fluorescence detection process, where the single chain DNA-gold nano-composite sample to be tested and then is connected with the donor substrate, and obtaining a second fluorescence quenching intensity by the fluorescence detection process, where the concentration of the standard substance and the first fluorescence quenching intensity are used to obtain the microcystic toxins in sample. The substrate comprises glass sheet, mica or silicon chip. The single chain DNA is acid nucleoside single chain gland or a single-chain thymine. The microcystin standard article concentration are respectively 10-4 mu g/L, 10-3 mu g/L, 10-2 mu g/L, 10-1 mu g/L, 1 mu g/L and 2.5 mu g/L.