▎ 摘　　要

NOVELTY - Method for detecting trypsin activity involves ultrasonically treating graphene oxide, then adding graphene oxide to thionin, adding ultra-pure water, filtering, drying filter residue to obtain complex, soaking the gold electrode in the soaking solution, polishing, grinding, immersing in ethanol solution and ultrapure water, ultrasonically treating, immersing the gold electrode in sulfuric acid solution, immersing the activated gold electrode in the polypeptide solution, leaving, adding 6-mercaptohexan-1-ol and distilled water, soaking to obtain self-assembled electrode, rinsing the self-assembled with wash buffer, soaking the self-assembling electrode in the wash buffer to obtain the modified electrode product, mixing trypsin with phosphate buffer, reacting with modified electrode product, adding the complex and ultrapure water to the reactants, continuing the reaction, rinsing with wash buffer and detecting trypsin by placing the rinsed reaction on the electrochemical station. USE - The method is useful for detecting trypsin activity. ADVANTAGE - The detection method is simple, improves the detection sensitivity, since graphene oxide has large specific surface area and loads large amount of thionin which functions as an electrochemical signal amplifier, removes non-specific adsorption and ensures that the prepared complex is adsorbed to the modified electrode product, since strong electrostatic interactions exist between carboxy-rich graphene oxide and positively charge histidine at the N-terminus of the substrate peptide. DETAILED DESCRIPTION - Method for detecting trypsin activity involves (a) ultrasonically treating graphene oxide, then adding graphene oxide to thionin, mixing the contents, adding ultra-pure water to mixture, filtering the mixed solution and drying filter residue to obtain complex, (b) mixing 80 %mass sulfuric acid solution with 30 %mass hydrogen peroxide to obtain gold electrode soaking solution, soaking the gold electrode in the gold electrode soaking solution, then rinsing with distilled water, polishing the gold electrode with 0.3 mu m alumina powder, grinding, immersing the gold electrode in 80 %mass ethanol solution and ultrapure water, ultrasonically treating for 5-10 minutes to obtain an ultrasonic gold electrode, immersing the gold electrode in 0.5 mol/l sulfuric acid solution and uniformly mixing to obtain an activated gold electrode, (c) adding substrate polypeptide to the 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer solution, stirring until complete dissolution to obtain a polypeptide solution, immersing the activated gold electrode in the polypeptide solution, leaving at 20-30 degrees C for 16-18 hours, rinsing the modified electrode with wash buffer, adding 6-mercaptohexan-1-ol and distilled water, soaking to obtain self-assembled electrode, rinsing the self-assembled with wash buffer and soaking the self-assembling electrode in the wash buffer to obtain the modified electrode product and (d) mixing trypsin with phosphate buffer, reacting the mixture with modified electrode product to obtain the reactants, adding the complex obtained in step (a) and ultrapure water to the reactants, continuing the reaction, rinsing with wash buffer and detecting trypsin by placing the rinsed reaction on the electrochemical station.