▎ 摘　　要

NOVELTY - Preparing gold-modified graphene electrode comprises (1) cleaning the glassy carbon sheet, (2) performing direct current plasma chemical vapor depositing, placing glassy carbon sheet obtained in step (1) into the sample chamber of the direct current plasma chemical vapor deposition device, vacuumizing, filling inert gas and hydrogen into the sample cavity so the pressure in the sample cavity is 3000-3500 Pa, heating 900-1100 degrees C, spraying methane into the sample chamber for 3-5 minutes, ending the direct current plasma chemical vapor deposition, where the spraying flow rate of methane is 0.15 -0.25 l/minutes, (3), using graphite glassy carbon sheet obtained in step (2) as the working electrode, taking the working electrode, three electrode system counter electrode and reference electrode and inserting into the electrolyte, connecting to the electrochemical working station. USE - The gold platinum co-modified graphene electrode is used as an immunosensor (claimed). ADVANTAGE - The electrode is suitable for quantitative detection of tumor markers with high accuracy. DETAILED DESCRIPTION - Preparing gold-modified graphene electrode comprises (1) cleaning the glassy carbon sheet, (2) performing direct current plasma chemical vapor depositing, placing glassy carbon sheet obtained in step (1) into the sample chamber of the direct current plasma chemical vapor deposition device, vacuumizing, filling inert gas and hydrogen into the sample cavity so the pressure in the sample cavity is 3000-3500 Pa, heating 900-1100 degrees C, spraying methane into the sample chamber for 3-5 minutes, ending the direct current plasma chemical vapor deposition, where the spraying flow rate of methane is 0.15 -0.25 l/minutes, (3), using graphite glassy carbon sheet obtained in step (2) as the working electrode, taking the working electrode, three electrode system counter electrode and reference electrode and inserting into the electrolyte, connecting to the electrochemical working station, using multipotential step method surface electrochemistry reductive precipitate the gold nano particle of the graphene glassy carbon sheet and the deposition time is 1-5 minutes, cleaning to obtain the platinum modified graphene electrode, where the electrolyte is mixed solution of tetrachloroauric acid and chloroplatinic acid. INDEPENDENT CLAIM are also included for gold platinum co-modified graphene electrode obtained by above mentioned method; and #use of platinum-modified graphite electrode as immune sensor comprising (a) using Ab1 the antibody solution in the platinum-modified graphene electrode into the specific, incubating for 2-3 hours under the constant temperature condition of 37 degrees C to obtain incubated with immune electrode of antibody Ab1, using phosphoric acid buffer solution to wash the surface of an electrode, adding in the bovine serum albumin solution with the concentration of 1-2 wt.% of the immune electrode, incubating under the constant temperature condition of 37 degrees C for 20-30 minutes, taking out the immune electrode using phosphoric acid buffer solution to wash the surface, (b) using specific antigen solution obtained from step (a) immune electrode immersed different concentration, where each time the immune electrode into specific antigen in solution after carrying out the following operation by carrying out incubation for 30-90 minutes under the constant temperature condition of 37 degrees C, taking out the immune electrode using phosphoric acid buffer solution to wash the surface, incubating immune electrode with specific antigen. taking label solution of 0.1-0.150 volume parts into the surface of the immune electrode, carrying out incubation for 20-30 minutes under the constant temperature condition of 37 degrees C, taking the immune electrode, using phosphoric acid buffer solution to wash the surface of the immune electrode, an electrode modified by the tag as the working electrode, the differential pulse voltampere curve of the immune electrode immune electrode into reference electrode, counter electrode and the tag-modified after removing oxygen in phosphoric acid buffer solution, modifying by test label, electric potential in a differential pulse voltampere curve -1 to 1V corresponding to the peak as the qualitative index, current corresponding to the qualitative index as the quantitative index to obtain solution quantitative index of a particular antigen in the specific antigen concentration, (c) drawing coordinate system, the coordinate system of the abscissa and ordinate are respectively specific antigen concentration and quantitative index, using step (b) a specific antigen solution of different concentration, the specific antigen concentration of each specific antigen solution and a quantitative index of drawing into the coordinate system at that specific antigen concentration to obtain the working curve, the working curve fitting to obtain a linear regression equation, (d) preparing the solution to be tested, differential pulse voltammetry curve (DPV) of the solution to be tested contains a specific antigen, obtaining the solution to be tested, potential in a differential pulse volt-ampere curve of the to-be-tested solution -1 to 1V at wave crest as a qualitative index corresponding to the current corresponding to the qualitative index as quantitative index, the quantitative index of the solution to be tested is substituted into the linear regression equation to obtain the concentration of the specific antigen in the test solution.