▎ 摘　　要

NOVELTY - Method for preparing a chemiluminescence sensor based on functionalized magnetic silica involves (a) preparing magnetic silica/aptamer, (b) preparing complementary strand DNA-graphene quantum dots, (c) preparing magnetic silica/aptamer-complementary strand DNA-graphene quantum dots using the magnetic silica/aptamer dispersion and complementary strand DNA-graphene quantum dot solution, (d) pretreating sample, and (e) preparing the chemiluminescence sensor by starting main pump and auxiliary pump of the flow injection chemical luminescence instrument, where the injection valve is in the injection position, combining sodium hydroxide, hydrogen peroxide, luminol solution and sample tube, flowing for 311 seconds, recording the intensity of chemiluminescence, retaining the solution in the sample tube, catalyzing the luminol-hydrogen peroxide-strong sodium oxide chemiluminescence system and realizing the quantitative detection of the target molecule. USE - The method is useful for preparing chemiluminescence sensor used for detecting thrombin. ADVANTAGE - The method provides theoretical support for detection of clinical thrombin and other biomarkers. DETAILED DESCRIPTION - Method for preparing a chemiluminescence sensor based on functionalized magnetic silica involves (a) preparing magnetic silica/aptamer by uniformly dispersing 0.05-0.10 g magnetic silica in 100 ml phosphate buffer with a pH 7-7.4, pipetting 1 ml dispersion into a 5 ml centrifuge tube, adding 0.5-2 mu mol aptamer to the tube, incubating with shaking at room temperature for 4-6 hours, separating composition in the tube under the action of an external magnet to remove unreacted aptamers, diluting the separated product to 50 ml with a phosphate buffer with a pH of 7-7.4 to obtain a magnetic silica/aptamer dispersion and storing in a 4 degrees C refrigerator, (b) preparing complementary strand DNA-graphene quantum dots by using a phosphate buffer with a pH of 7-7.4 to prepare graphene quantum dots into 25 ml graphene quantum dot solution with a concentration of 1-2.5 mu mol/l, pipetting 2 ml solution into a 5 ml centrifuge tube, adding 1-2.5 mu mol complementary strand DNA, incubating with shaking at room temperature for 4-6 hours, centrifuging at 8000 revolutions/minute (rpm) for 5-10 minutes to remove complementary strand DNA that failed to bind to the graphene quantum dots, diluting the separated product to 50 ml with a phosphate buffer with a pH of 7-7.4 to obtain complementary strand DNA-graphene quantum dot solution and placing in a refrigerator at 4 degrees C, (c) preparing magnetic silica/aptamer-complementary strand DNA-graphene quantum dots by pipetting 2-5 ml magnetic silica/aptamer dispersion prepared in (a), centrifuging, adding 3-6 ml complementary strand DNA-graphene quantum dot solution prepared in step (b), incubating with shaking at room temperature for 3-5 hours, separating the composition in the tube under the action of an external magnet to remove unreacted complementary strand DNA-graphene quantum dots, diluting the separated product to 50 ml with a phosphate buffer with a pH of 7-7.4 to obtain a magnetic silica/aptamer-complementary strand DNA-graphene quantum dot dispersion and storing in a 4 degrees C refrigerator, (d) pretreating sample to be tested by diluting the sample to be tested with a phosphate buffer with a pH of 7-7.4 to 100-1000 times, taking 5 ml diluted test solution, placing into a 25 ml colorimetric tube, then adding 2-5 ml magnetic silica/aptamer-complementary strand DNA-graphene quantum dot dispersion into the colorimetric tube, tightly combining the analyte molecule and aptamer in the centrifuge tube due to specific recognition to form a magnetic silica/aptamer-the analyte molecule, separating complementary strand DNA-graphene quantum dots from magnetic silica/aptamer, magnetically separating the composition in the tube under the action of an external magnet, and reserving the supernatant for subsequent testing, and (e) preparing the chemiluminescence sensor by starting main pump and auxiliary pump of the flow injection chemical luminescence instrument, where the injection valve is in the injection position, combining sodium hydroxide, hydrogen peroxide, luminol solution and sample tube, flowing for 311 seconds, recording the intensity of chemiluminescence, which is the intensity of chemiluminescence corresponding to a certain concentration of analyte molecules, retaining the solution in the sample tube, allowing the complementary strand DNA-graphene quantum dots in the supernatant to catalyze the luminol-hydrogen peroxide-strong sodium oxide chemiluminescence system, causing changes in the chemical luminescence intensity and realizing the quantitative detection of the target molecule.