▎ 摘　　要

NOVELTY - Method for preparing polyaniline covalently modified magnetic graphene oxide and complementary strand DNA modified cobalt porphyrin, involves (i) preparing magnetic graphene oxide covalently modified with polyaniline by adding hydrochloric acid solution to a three-necked flask, adding purified aniline, adding magnetic graphene oxide, magnetically stirring, slowly adding ammonium persulfate solution, dripping, continuously reacting in an ice bath environment, washing the product with ultrapure water until the filtrate is colorless, collecting the product by an external magnetic field, drying in a vacuum drying oven and grinding, and (ii) preparing cobalt porphyrin modified with complementary strand DNA by pipetting cobalt porphyrin solution into a centrifuge tube, adding complementary strand DNA, incubating with shaking, separating, discarding supernatant to remove the unreacted complementary strand DNA, transferring the product to a volumetric flask and storing at 4 degrees C. USE - The method is used for preparing polyaniline covalently modified magnetic graphene oxide and complementary strand DNA modified cobalt porphyrin for preparing chemiluminescence sensor. ADVANTAGE - The method realizes the target DNA detection of different sequences. DETAILED DESCRIPTION - Method for preparing polyaniline covalently modified magnetic graphene oxide and complementary strand DNA modified cobalt porphyrin, involves (i) preparing magnetic graphene oxide covalently modified with polyaniline by adding 30-50 ml 1-2.5 mol/l hydrochloric acid solution to a 100 ml three-necked flask, adding 1-2.5 g purified aniline, adding 0.1-0.25 g magnetic graphene oxide, magnetically stirring for 0.5-2 hours in an ice bath environment to make it fully dispersed, slowly adding 10-30 ml 1-2.5 mol/l ammonium persulfate solution, and the dropping rate is controlled at 0.08-0.12 ml/minute, dripping, continuously reacting for 1-2 hours in an ice bath environment, washing the product 3-5 times with ultrapure water until the filtrate is colorless, collecting the product by an external magnetic field, drying in a vacuum drying oven at 50-80 degrees C for 8-12 hours and grinding, and (ii) preparing cobalt porphyrin modified with complementary strand DNA by pipetting 1-2.5 ml 0.1-0.5 mmol/l cobalt porphyrin solution into a 5 ml centrifuge tube, adding 0.1-0.5 ml 50-80 mu mol/l complementary strand DNA, incubating with shaking at room temperature for 2-5 hours, centrifugally separating at 8000-10000 radian/minute for 3-5 minutes, discarding the supernatant to remove the unreacted complementary strand DNA, transferring the product to a 25 ml volumetric flask and storing at 4 degrees C. An INDEPENDENT CLAIM is included for a method for preparing chemiluminescence sensor based on polyaniline adsorption of double-stranded DNA, which has detection principles such as, when there is no target DNA to be detected, the magnetic graphene oxide covalently modified with polyaniline does not fix the single-stranded complementary strand of DNA, after magnetic separation by magnet, the content of cobalt porphyrin modified with complementary strand DNA in the supernatant does not change, and the catalytic performance of chemiluminescence reaction does not change, and when the target DNA to be detected is present, it performs base complementary pairing with the complementary strand of DNA to form double-stranded DNA, the formed double-stranded DNA-porphyrin cobalt is immobilized on the surface of magnetic graphene oxide covalently modified with polyaniline, and after magnetic separation by a magnet, the content of cobalt porphyrin modified with complementary strand DNA in the supernatant is reduced, so that the catalytic performance of the chemiluminescence reaction is reduced, so as to achieve the detection of the target DNA content.