▎ 摘　　要

NOVELTY - Detecting thrombin content comprises (i) drawing the fluorescence standard curve of thrombin, including (a) ultrasonically treating the graphene oxide in an aqueous solution to obtain a graphene oxide dispersion, (b) mixing the DNA containing aptamer and different concentrations of thrombin in Tris-HAc buffer respectively and incubating with silver nitrate and copper(II) nitrate and incubating in the dark, adding sodium borohydride to mix and incubating to reduce silver ion and copper ion to silver and copper to obtain a DNA-copper/silver nanocluster solution combined with thrombin and aptamer, (c) adding the graphene oxide dispersion into the DNA-copper/silver nanocluster solution of thrombin and aptamer and incubating, measuring each mixture separately, drawing a standard curve based on the maximum fluorescence emission value for the fluorescence value corresponding to the solution. USE - The method is useful for detecting thrombin content. ADVANTAGE - The method eliminates the background fluorescence, avoids the non-specific adsorption of the graphene oxide to the thrombin, reduces the modification step of the graphene oxide, has the linear range of 2-10 nM, the lowest detection limit of 0.25 nM, simple operation, high sensitivity, good selectivity, small toxicity, good biological compatibility, no mark and is economical. DETAILED DESCRIPTION - Detecting thrombin content comprises (i) drawing the fluorescence standard curve of thrombin, including (a) ultrasonically treating the graphene oxide in an aqueous solution to obtain a graphene oxide dispersion, (b) mixing the DNA containing aptamer and different concentrations of thrombin in Tris-HAc buffer respectively and incubating with silver nitrate and copper(II) nitrate and incubating in the dark, adding sodium borohydride to mix and incubating to reduce silver ion and copper ion to silver and copper to obtain a DNA-copper/silver nanocluster solution combined with thrombin and aptamer, (c) adding the graphene oxide dispersion into the DNA-copper/silver nanocluster solution of thrombin and aptamer and incubating, measuring each mixture separately, drawing a standard curve based on the maximum fluorescence emission value for the fluorescence value corresponding to the solution; (ii) mixing the sample solution to be tested and the DNA containing the aptamer in Tris-HAc buffer and incubate, adding silver nitrate and copper(II) nitrate and incubate in the dark, adding sodium borohydride to mix and incubate, adding the graphene oxide dispersion liquid and uniformly mixing and incubating to measure the fluorescence value of the mixed solution; and (iii) according to the standard curve, calculating the content of thrombin in the sample solution to be tested.